diff --git a/api/common.go b/api/common.go
index 866ad8f676f63..b11c2fe02b12a 100644
--- a/api/common.go
+++ b/api/common.go
@@ -2,9 +2,18 @@ package api // import "github.com/docker/docker/api"
 
 // Common constants for daemon and client.
 const (
-	// DefaultVersion of Current REST API
+	// DefaultVersion of the current REST API.
 	DefaultVersion = "1.45"
 
+	// MinSupportedAPIVersion is the minimum API version that can be supported
+	// by the API server, specified as "major.minor". Note that the daemon
+	// may be configured with a different minimum API version, as returned
+	// in [github.com/docker/docker/api/types.Version.MinAPIVersion].
+	//
+	// API requests for API versions lower than the configured version produce
+	// an error.
+	MinSupportedAPIVersion = "1.24"
+
 	// NoBaseImageSpecifier is the symbol used by the FROM
 	// command to specify that no base image is to be used.
 	NoBaseImageSpecifier = "scratch"
diff --git a/api/server/errorhandler.go b/api/server/errorhandler.go
deleted file mode 100644
index 71a0c13c8423c..0000000000000
--- a/api/server/errorhandler.go
+++ /dev/null
@@ -1,34 +0,0 @@
-package server
-
-import (
-	"net/http"
-
-	"github.com/docker/docker/api/server/httpstatus"
-	"github.com/docker/docker/api/server/httputils"
-	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/versions"
-	"github.com/gorilla/mux"
-	"google.golang.org/grpc/status"
-)
-
-// makeErrorHandler makes an HTTP handler that decodes a Docker error and
-// returns it in the response.
-func makeErrorHandler(err error) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		statusCode := httpstatus.FromError(err)
-		vars := mux.Vars(r)
-		if apiVersionSupportsJSONErrors(vars["version"]) {
-			response := &types.ErrorResponse{
-				Message: err.Error(),
-			}
-			_ = httputils.WriteJSON(w, statusCode, response)
-		} else {
-			http.Error(w, status.Convert(err).Message(), statusCode)
-		}
-	}
-}
-
-func apiVersionSupportsJSONErrors(version string) bool {
-	const firstAPIVersionWithJSONErrors = "1.23"
-	return version == "" || versions.GreaterThan(version, firstAPIVersionWithJSONErrors)
-}
diff --git a/api/server/httputils/decoder.go b/api/server/httputils/decoder.go
index 8293503c48162..c254e8e31296e 100644
--- a/api/server/httputils/decoder.go
+++ b/api/server/httputils/decoder.go
@@ -12,5 +12,4 @@ import (
 // container configuration.
 type ContainerDecoder interface {
 	DecodeConfig(src io.Reader) (*container.Config, *container.HostConfig, *network.NetworkingConfig, error)
-	DecodeHostConfig(src io.Reader) (*container.HostConfig, error)
 }
diff --git a/api/server/middleware/version.go b/api/server/middleware/version.go
index 1a4b3bedef418..6bd181ffebf19 100644
--- a/api/server/middleware/version.go
+++ b/api/server/middleware/version.go
@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"runtime"
 
+	"github.com/docker/docker/api"
 	"github.com/docker/docker/api/server/httputils"
 	"github.com/docker/docker/api/types/versions"
 )
@@ -13,19 +14,40 @@ import (
 // VersionMiddleware is a middleware that
 // validates the client and server versions.
 type VersionMiddleware struct {
-	serverVersion  string
-	defaultVersion string
-	minVersion     string
+	serverVersion string
+
+	// defaultAPIVersion is the default API version provided by the API server,
+	// specified as "major.minor". It is usually configured to the latest API
+	// version [github.com/docker/docker/api.DefaultVersion].
+	//
+	// API requests for API versions greater than this version are rejected by
+	// the server and produce a [versionUnsupportedError].
+	defaultAPIVersion string
+
+	// minAPIVersion is the minimum API version provided by the API server,
+	// specified as "major.minor".
+	//
+	// API requests for API versions lower than this version are rejected by
+	// the server and produce a [versionUnsupportedError].
+	minAPIVersion string
 }
 
-// NewVersionMiddleware creates a new VersionMiddleware
-// with the default versions.
-func NewVersionMiddleware(s, d, m string) VersionMiddleware {
-	return VersionMiddleware{
-		serverVersion:  s,
-		defaultVersion: d,
-		minVersion:     m,
+// NewVersionMiddleware creates a VersionMiddleware with the given versions.
+func NewVersionMiddleware(serverVersion, defaultAPIVersion, minAPIVersion string) (*VersionMiddleware, error) {
+	if versions.LessThan(defaultAPIVersion, api.MinSupportedAPIVersion) || versions.GreaterThan(defaultAPIVersion, api.DefaultVersion) {
+		return nil, fmt.Errorf("invalid default API version (%s): must be between %s and %s", defaultAPIVersion, api.MinSupportedAPIVersion, api.DefaultVersion)
+	}
+	if versions.LessThan(minAPIVersion, api.MinSupportedAPIVersion) || versions.GreaterThan(minAPIVersion, api.DefaultVersion) {
+		return nil, fmt.Errorf("invalid minimum API version (%s): must be between %s and %s", minAPIVersion, api.MinSupportedAPIVersion, api.DefaultVersion)
+	}
+	if versions.GreaterThan(minAPIVersion, defaultAPIVersion) {
+		return nil, fmt.Errorf("invalid API version: the minimum API version (%s) is higher than the default version (%s)", minAPIVersion, defaultAPIVersion)
 	}
+	return &VersionMiddleware{
+		serverVersion:     serverVersion,
+		defaultAPIVersion: defaultAPIVersion,
+		minAPIVersion:     minAPIVersion,
+	}, nil
 }
 
 type versionUnsupportedError struct {
@@ -45,18 +67,18 @@ func (e versionUnsupportedError) InvalidParameter() {}
 func (v VersionMiddleware) WrapHandler(handler func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error) func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 	return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 		w.Header().Set("Server", fmt.Sprintf("Docker/%s (%s)", v.serverVersion, runtime.GOOS))
-		w.Header().Set("API-Version", v.defaultVersion)
+		w.Header().Set("API-Version", v.defaultAPIVersion)
 		w.Header().Set("OSType", runtime.GOOS)
 
 		apiVersion := vars["version"]
 		if apiVersion == "" {
-			apiVersion = v.defaultVersion
+			apiVersion = v.defaultAPIVersion
 		}
-		if versions.LessThan(apiVersion, v.minVersion) {
-			return versionUnsupportedError{version: apiVersion, minVersion: v.minVersion}
+		if versions.LessThan(apiVersion, v.minAPIVersion) {
+			return versionUnsupportedError{version: apiVersion, minVersion: v.minAPIVersion}
 		}
-		if versions.GreaterThan(apiVersion, v.defaultVersion) {
-			return versionUnsupportedError{version: apiVersion, maxVersion: v.defaultVersion}
+		if versions.GreaterThan(apiVersion, v.defaultAPIVersion) {
+			return versionUnsupportedError{version: apiVersion, maxVersion: v.defaultAPIVersion}
 		}
 		ctx = context.WithValue(ctx, httputils.APIVersionKey{}, apiVersion)
 		return handler(ctx, w, r, vars)
diff --git a/api/server/middleware/version_test.go b/api/server/middleware/version_test.go
index a102f8e6c4daf..1c7888bd95b42 100644
--- a/api/server/middleware/version_test.go
+++ b/api/server/middleware/version_test.go
@@ -2,27 +2,82 @@ package middleware // import "github.com/docker/docker/api/server/middleware"
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"runtime"
 	"testing"
 
+	"github.com/docker/docker/api"
 	"github.com/docker/docker/api/server/httputils"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
 )
 
+func TestNewVersionMiddlewareValidation(t *testing.T) {
+	tests := []struct {
+		doc, defaultVersion, minVersion, expectedErr string
+	}{
+		{
+			doc:            "defaults",
+			defaultVersion: api.DefaultVersion,
+			minVersion:     api.MinSupportedAPIVersion,
+		},
+		{
+			doc:            "invalid default lower than min",
+			defaultVersion: api.MinSupportedAPIVersion,
+			minVersion:     api.DefaultVersion,
+			expectedErr:    fmt.Sprintf("invalid API version: the minimum API version (%s) is higher than the default version (%s)", api.DefaultVersion, api.MinSupportedAPIVersion),
+		},
+		{
+			doc:            "invalid default too low",
+			defaultVersion: "0.1",
+			minVersion:     api.MinSupportedAPIVersion,
+			expectedErr:    fmt.Sprintf("invalid default API version (0.1): must be between %s and %s", api.MinSupportedAPIVersion, api.DefaultVersion),
+		},
+		{
+			doc:            "invalid default too high",
+			defaultVersion: "9999.9999",
+			minVersion:     api.DefaultVersion,
+			expectedErr:    fmt.Sprintf("invalid default API version (9999.9999): must be between %s and %s", api.MinSupportedAPIVersion, api.DefaultVersion),
+		},
+		{
+			doc:            "invalid minimum too low",
+			defaultVersion: api.MinSupportedAPIVersion,
+			minVersion:     "0.1",
+			expectedErr:    fmt.Sprintf("invalid minimum API version (0.1): must be between %s and %s", api.MinSupportedAPIVersion, api.DefaultVersion),
+		},
+		{
+			doc:            "invalid minimum too high",
+			defaultVersion: api.DefaultVersion,
+			minVersion:     "9999.9999",
+			expectedErr:    fmt.Sprintf("invalid minimum API version (9999.9999): must be between %s and %s", api.MinSupportedAPIVersion, api.DefaultVersion),
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.doc, func(t *testing.T) {
+			_, err := NewVersionMiddleware("1.2.3", tc.defaultVersion, tc.minVersion)
+			if tc.expectedErr == "" {
+				assert.Check(t, err)
+			} else {
+				assert.Check(t, is.Error(err, tc.expectedErr))
+			}
+		})
+	}
+}
+
 func TestVersionMiddlewareVersion(t *testing.T) {
-	defaultVersion := "1.10.0"
-	minVersion := "1.2.0"
-	expectedVersion := defaultVersion
+	expectedVersion := "<not set>"
 	handler := func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 		v := httputils.VersionFromContext(ctx)
 		assert.Check(t, is.Equal(expectedVersion, v))
 		return nil
 	}
 
-	m := NewVersionMiddleware(defaultVersion, defaultVersion, minVersion)
+	m, err := NewVersionMiddleware("1.2.3", api.DefaultVersion, api.MinSupportedAPIVersion)
+	assert.NilError(t, err)
 	h := m.WrapHandler(handler)
 
 	req, _ := http.NewRequest(http.MethodGet, "/containers/json", nil)
@@ -35,19 +90,19 @@ func TestVersionMiddlewareVersion(t *testing.T) {
 		errString       string
 	}{
 		{
-			expectedVersion: "1.10.0",
+			expectedVersion: api.DefaultVersion,
 		},
 		{
-			reqVersion:      "1.9.0",
-			expectedVersion: "1.9.0",
+			reqVersion:      api.MinSupportedAPIVersion,
+			expectedVersion: api.MinSupportedAPIVersion,
 		},
 		{
 			reqVersion: "0.1",
-			errString:  "client version 0.1 is too old. Minimum supported API version is 1.2.0, please upgrade your client to a newer version",
+			errString:  fmt.Sprintf("client version 0.1 is too old. Minimum supported API version is %s, please upgrade your client to a newer version", api.MinSupportedAPIVersion),
 		},
 		{
 			reqVersion: "9999.9999",
-			errString:  "client version 9999.9999 is too new. Maximum supported API version is 1.10.0",
+			errString:  fmt.Sprintf("client version 9999.9999 is too new. Maximum supported API version is %s", api.DefaultVersion),
 		},
 	}
 
@@ -71,9 +126,8 @@ func TestVersionMiddlewareWithErrorsReturnsHeaders(t *testing.T) {
 		return nil
 	}
 
-	defaultVersion := "1.10.0"
-	minVersion := "1.2.0"
-	m := NewVersionMiddleware(defaultVersion, defaultVersion, minVersion)
+	m, err := NewVersionMiddleware("1.2.3", api.DefaultVersion, api.MinSupportedAPIVersion)
+	assert.NilError(t, err)
 	h := m.WrapHandler(handler)
 
 	req, _ := http.NewRequest(http.MethodGet, "/containers/json", nil)
@@ -81,12 +135,12 @@ func TestVersionMiddlewareWithErrorsReturnsHeaders(t *testing.T) {
 	ctx := context.Background()
 
 	vars := map[string]string{"version": "0.1"}
-	err := h(ctx, resp, req, vars)
+	err = h(ctx, resp, req, vars)
 	assert.Check(t, is.ErrorContains(err, ""))
 
 	hdr := resp.Result().Header
-	assert.Check(t, is.Contains(hdr.Get("Server"), "Docker/"+defaultVersion))
+	assert.Check(t, is.Contains(hdr.Get("Server"), "Docker/1.2.3"))
 	assert.Check(t, is.Contains(hdr.Get("Server"), runtime.GOOS))
-	assert.Check(t, is.Equal(hdr.Get("API-Version"), defaultVersion))
+	assert.Check(t, is.Equal(hdr.Get("API-Version"), api.DefaultVersion))
 	assert.Check(t, is.Equal(hdr.Get("OSType"), runtime.GOOS))
 }
diff --git a/api/server/router/build/build_routes.go b/api/server/router/build/build_routes.go
index 0da19e61c9e7b..186e8e483b38e 100644
--- a/api/server/router/build/build_routes.go
+++ b/api/server/router/build/build_routes.go
@@ -42,6 +42,7 @@ func newImageBuildOptions(ctx context.Context, r *http.Request) (*types.ImageBui
 		SuppressOutput: httputils.BoolValue(r, "q"),
 		NoCache:        httputils.BoolValue(r, "nocache"),
 		ForceRemove:    httputils.BoolValue(r, "forcerm"),
+		PullParent:     httputils.BoolValue(r, "pull"),
 		MemorySwap:     httputils.Int64ValueOrZero(r, "memswap"),
 		Memory:         httputils.Int64ValueOrZero(r, "memory"),
 		CPUShares:      httputils.Int64ValueOrZero(r, "cpushares"),
@@ -66,17 +67,14 @@ func newImageBuildOptions(ctx context.Context, r *http.Request) (*types.ImageBui
 		return nil, invalidParam{errors.New("security options are not supported on " + runtime.GOOS)}
 	}
 
-	version := httputils.VersionFromContext(ctx)
-	if httputils.BoolValue(r, "forcerm") && versions.GreaterThanOrEqualTo(version, "1.12") {
+	if httputils.BoolValue(r, "forcerm") {
 		options.Remove = true
-	} else if r.FormValue("rm") == "" && versions.GreaterThanOrEqualTo(version, "1.12") {
+	} else if r.FormValue("rm") == "" {
 		options.Remove = true
 	} else {
 		options.Remove = httputils.BoolValue(r, "rm")
 	}
-	if httputils.BoolValue(r, "pull") && versions.GreaterThanOrEqualTo(version, "1.16") {
-		options.PullParent = true
-	}
+	version := httputils.VersionFromContext(ctx)
 	if versions.GreaterThanOrEqualTo(version, "1.32") {
 		options.Platform = r.FormValue("platform")
 	}
diff --git a/api/server/router/container/backend.go b/api/server/router/container/backend.go
index fa1c0dcc54076..cc7e8f6767f8f 100644
--- a/api/server/router/container/backend.go
+++ b/api/server/router/container/backend.go
@@ -24,7 +24,6 @@ type execBackend interface {
 // copyBackend includes functions to implement to provide container copy functionality.
 type copyBackend interface {
 	ContainerArchivePath(name string, path string) (content io.ReadCloser, stat *types.ContainerPathStat, err error)
-	ContainerCopy(name string, res string) (io.ReadCloser, error)
 	ContainerExport(ctx context.Context, name string, out io.Writer) error
 	ContainerExtractToDir(name, path string, copyUIDGID, noOverwriteDirNonDir bool, content io.Reader) error
 	ContainerStatPath(name string, path string) (stat *types.ContainerPathStat, err error)
@@ -39,7 +38,7 @@ type stateBackend interface {
 	ContainerResize(name string, height, width int) error
 	ContainerRestart(ctx context.Context, name string, options container.StopOptions) error
 	ContainerRm(name string, config *backend.ContainerRmConfig) error
-	ContainerStart(ctx context.Context, name string, hostConfig *container.HostConfig, checkpoint string, checkpointDir string) error
+	ContainerStart(ctx context.Context, name string, checkpoint string, checkpointDir string) error
 	ContainerStop(ctx context.Context, name string, options container.StopOptions) error
 	ContainerUnpause(name string) error
 	ContainerUpdate(name string, hostConfig *container.HostConfig) (container.ContainerUpdateOKBody, error)
diff --git a/api/server/router/container/container.go b/api/server/router/container/container.go
index 7ac9dc7aac20c..ebe5f082c11a8 100644
--- a/api/server/router/container/container.go
+++ b/api/server/router/container/container.go
@@ -56,7 +56,6 @@ func (r *containerRouter) initRoutes() {
 		router.NewPostRoute("/containers/{name:.*}/wait", r.postContainersWait),
 		router.NewPostRoute("/containers/{name:.*}/resize", r.postContainersResize),
 		router.NewPostRoute("/containers/{name:.*}/attach", r.postContainersAttach),
-		router.NewPostRoute("/containers/{name:.*}/copy", r.postContainersCopy), // Deprecated since 1.8 (API v1.20), errors out since 1.12 (API v1.24)
 		router.NewPostRoute("/containers/{name:.*}/exec", r.postContainerExecCreate),
 		router.NewPostRoute("/exec/{name:.*}/start", r.postContainerExecStart),
 		router.NewPostRoute("/exec/{name:.*}/resize", r.postContainerExecResize),
diff --git a/api/server/router/container/container_routes.go b/api/server/router/container/container_routes.go
index dbb2b9beda5fe..5c173aade43d7 100644
--- a/api/server/router/container/container_routes.go
+++ b/api/server/router/container/container_routes.go
@@ -39,13 +39,6 @@ func (s *containerRouter) postCommit(ctx context.Context, w http.ResponseWriter,
 		return err
 	}
 
-	// TODO: remove pause arg, and always pause in backend
-	pause := httputils.BoolValue(r, "pause")
-	version := httputils.VersionFromContext(ctx)
-	if r.FormValue("pause") == "" && versions.GreaterThanOrEqualTo(version, "1.13") {
-		pause = true
-	}
-
 	config, _, _, err := s.decoder.DecodeConfig(r.Body)
 	if err != nil && !errors.Is(err, io.EOF) { // Do not fail if body is empty.
 		return err
@@ -57,7 +50,7 @@ func (s *containerRouter) postCommit(ctx context.Context, w http.ResponseWriter,
 	}
 
 	imgID, err := s.backend.CreateImageFromContainer(ctx, r.Form.Get("container"), &backend.CreateImageConfig{
-		Pause:   pause,
+		Pause:   httputils.BoolValueOrDefault(r, "pause", true), // TODO(dnephin): remove pause arg, and always pause in backend
 		Tag:     ref,
 		Author:  r.Form.Get("author"),
 		Comment: r.Form.Get("comment"),
@@ -118,14 +111,11 @@ func (s *containerRouter) getContainersStats(ctx context.Context, w http.Respons
 		oneShot = httputils.BoolValueOrDefault(r, "one-shot", false)
 	}
 
-	config := &backend.ContainerStatsConfig{
+	return s.backend.ContainerStats(ctx, vars["name"], &backend.ContainerStatsConfig{
 		Stream:    stream,
 		OneShot:   oneShot,
 		OutStream: w,
-		Version:   httputils.VersionFromContext(ctx),
-	}
-
-	return s.backend.ContainerStats(ctx, vars["name"], config)
+	})
 }
 
 func (s *containerRouter) getContainersLogs(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
@@ -178,14 +168,6 @@ func (s *containerRouter) getContainersExport(ctx context.Context, w http.Respon
 	return s.backend.ContainerExport(ctx, vars["name"], w)
 }
 
-type bodyOnStartError struct{}
-
-func (bodyOnStartError) Error() string {
-	return "starting container with non-empty request body was deprecated since API v1.22 and removed in v1.24"
-}
-
-func (bodyOnStartError) InvalidParameter() {}
-
 func (s *containerRouter) postContainersStart(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 	// If contentLength is -1, we can assumed chunked encoding
 	// or more technically that the length is unknown
@@ -193,33 +175,17 @@ func (s *containerRouter) postContainersStart(ctx context.Context, w http.Respon
 	// net/http otherwise seems to swallow any headers related to chunked encoding
 	// including r.TransferEncoding
 	// allow a nil body for backwards compatibility
-
-	version := httputils.VersionFromContext(ctx)
-	var hostConfig *container.HostConfig
+	//
 	// A non-nil json object is at least 7 characters.
 	if r.ContentLength > 7 || r.ContentLength == -1 {
-		if versions.GreaterThanOrEqualTo(version, "1.24") {
-			return bodyOnStartError{}
-		}
-
-		if err := httputils.CheckForJSON(r); err != nil {
-			return err
-		}
-
-		c, err := s.decoder.DecodeHostConfig(r.Body)
-		if err != nil {
-			return err
-		}
-		hostConfig = c
+		return errdefs.InvalidParameter(errors.New("starting container with non-empty request body was deprecated since API v1.22 and removed in v1.24"))
 	}
 
 	if err := httputils.ParseForm(r); err != nil {
 		return err
 	}
 
-	checkpoint := r.Form.Get("checkpoint")
-	checkpointDir := r.Form.Get("checkpoint-dir")
-	if err := s.backend.ContainerStart(ctx, vars["name"], hostConfig, checkpoint, checkpointDir); err != nil {
+	if err := s.backend.ContainerStart(ctx, vars["name"], r.Form.Get("checkpoint"), r.Form.Get("checkpoint-dir")); err != nil {
 		return err
 	}
 
@@ -255,25 +221,14 @@ func (s *containerRouter) postContainersStop(ctx context.Context, w http.Respons
 	return nil
 }
 
-func (s *containerRouter) postContainersKill(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
+func (s *containerRouter) postContainersKill(_ context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
 	if err := httputils.ParseForm(r); err != nil {
 		return err
 	}
 
 	name := vars["name"]
 	if err := s.backend.ContainerKill(name, r.Form.Get("signal")); err != nil {
-		var isStopped bool
-		if errdefs.IsConflict(err) {
-			isStopped = true
-		}
-
-		// Return error that's not caused because the container is stopped.
-		// Return error if the container is not running and the api is >= 1.20
-		// to keep backwards compatibility.
-		version := httputils.VersionFromContext(ctx)
-		if versions.GreaterThanOrEqualTo(version, "1.20") || !isStopped {
-			return errors.Wrapf(err, "Cannot kill container: %s", name)
-		}
+		return errors.Wrapf(err, "cannot kill container: %s", name)
 	}
 
 	w.WriteHeader(http.StatusNoContent)
@@ -512,7 +467,6 @@ func (s *containerRouter) postContainersCreate(ctx context.Context, w http.Respo
 	}
 
 	version := httputils.VersionFromContext(ctx)
-	adjustCPUShares := versions.LessThan(version, "1.19")
 
 	// When using API 1.24 and under, the client is responsible for removing the container
 	if versions.LessThan(version, "1.25") {
@@ -656,7 +610,6 @@ func (s *containerRouter) postContainersCreate(ctx context.Context, w http.Respo
 		Config:           config,
 		HostConfig:       hostConfig,
 		NetworkingConfig: networkingConfig,
-		AdjustCPUShares:  adjustCPUShares,
 		Platform:         platform,
 	})
 	if err != nil {
diff --git a/api/server/router/container/copy.go b/api/server/router/container/copy.go
index 28920b6d7b7a7..7596818e5697f 100644
--- a/api/server/router/container/copy.go
+++ b/api/server/router/container/copy.go
@@ -11,49 +11,10 @@ import (
 
 	"github.com/docker/docker/api/server/httputils"
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/versions"
 	gddohttputil "github.com/golang/gddo/httputil"
 )
 
-type pathError struct{}
-
-func (pathError) Error() string {
-	return "Path cannot be empty"
-}
-
-func (pathError) InvalidParameter() {}
-
-// postContainersCopy is deprecated in favor of getContainersArchive.
-//
-// Deprecated since 1.8 (API v1.20), errors out since 1.12 (API v1.24)
-func (s *containerRouter) postContainersCopy(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-	version := httputils.VersionFromContext(ctx)
-	if versions.GreaterThanOrEqualTo(version, "1.24") {
-		w.WriteHeader(http.StatusNotFound)
-		return nil
-	}
-
-	cfg := types.CopyConfig{}
-	if err := httputils.ReadJSON(r, &cfg); err != nil {
-		return err
-	}
-
-	if cfg.Resource == "" {
-		return pathError{}
-	}
-
-	data, err := s.backend.ContainerCopy(vars["name"], cfg.Resource)
-	if err != nil {
-		return err
-	}
-	defer data.Close()
-
-	w.Header().Set("Content-Type", "application/x-tar")
-	_, err = io.Copy(w, data)
-	return err
-}
-
-// // Encode the stat to JSON, base64 encode, and place in a header.
+// setContainerPathStatHeader encodes the stat to JSON, base64 encode, and place in a header.
 func setContainerPathStatHeader(stat *types.ContainerPathStat, header http.Header) error {
 	statJSON, err := json.Marshal(stat)
 	if err != nil {
diff --git a/api/server/router/container/exec.go b/api/server/router/container/exec.go
index 619355a50a7ed..b62342af8525a 100644
--- a/api/server/router/container/exec.go
+++ b/api/server/router/container/exec.go
@@ -71,15 +71,6 @@ func (s *containerRouter) postContainerExecStart(ctx context.Context, w http.Res
 		return err
 	}
 
-	version := httputils.VersionFromContext(ctx)
-	if versions.LessThan(version, "1.22") {
-		// API versions before 1.22 did not enforce application/json content-type.
-		// Allow older clients to work by patching the content-type.
-		if r.Header.Get("Content-Type") != "application/json" {
-			r.Header.Set("Content-Type", "application/json")
-		}
-	}
-
 	var (
 		execName                  = vars["name"]
 		stdin, inStream           io.ReadCloser
@@ -96,6 +87,8 @@ func (s *containerRouter) postContainerExecStart(ctx context.Context, w http.Res
 	}
 
 	if execStartCheck.ConsoleSize != nil {
+		version := httputils.VersionFromContext(ctx)
+
 		// Not supported before 1.42
 		if versions.LessThan(version, "1.42") {
 			execStartCheck.ConsoleSize = nil
diff --git a/api/server/server.go b/api/server/server.go
index 3855197fa25fa..5e90d305a9738 100644
--- a/api/server/server.go
+++ b/api/server/server.go
@@ -10,6 +10,7 @@ import (
 	"github.com/docker/docker/api/server/middleware"
 	"github.com/docker/docker/api/server/router"
 	"github.com/docker/docker/api/server/router/debug"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/dockerversion"
 	"github.com/gorilla/mux"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
@@ -57,19 +58,13 @@ func (s *Server) makeHTTPHandler(handler httputils.APIFunc, operation string) ht
 			if statusCode >= 500 {
 				log.G(ctx).Errorf("Handler for %s %s returned error: %v", r.Method, r.URL.Path, err)
 			}
-			makeErrorHandler(err)(w, r)
+			_ = httputils.WriteJSON(w, statusCode, &types.ErrorResponse{
+				Message: err.Error(),
+			})
 		}
 	}), operation).ServeHTTP
 }
 
-type pageNotFoundError struct{}
-
-func (pageNotFoundError) Error() string {
-	return "page not found"
-}
-
-func (pageNotFoundError) NotFound() {}
-
 // CreateMux returns a new mux with all the routers registered.
 func (s *Server) CreateMux(routers ...router.Router) *mux.Router {
 	m := mux.NewRouter()
@@ -91,7 +86,12 @@ func (s *Server) CreateMux(routers ...router.Router) *mux.Router {
 		m.Path("/debug" + r.Path()).Handler(f)
 	}
 
-	notFoundHandler := makeErrorHandler(pageNotFoundError{})
+	notFoundHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_ = httputils.WriteJSON(w, http.StatusNotFound, &types.ErrorResponse{
+			Message: "page not found",
+		})
+	})
+
 	m.HandleFunc(versionMatcher+"/{path:.*}", notFoundHandler)
 	m.NotFoundHandler = notFoundHandler
 	m.MethodNotAllowedHandler = notFoundHandler
diff --git a/api/server/server_test.go b/api/server/server_test.go
index 65dda95c9cbdf..cf8b0568aa663 100644
--- a/api/server/server_test.go
+++ b/api/server/server_test.go
@@ -15,8 +15,11 @@ import (
 func TestMiddlewares(t *testing.T) {
 	srv := &Server{}
 
-	const apiMinVersion = "1.12"
-	srv.UseMiddleware(middleware.NewVersionMiddleware("0.1omega2", api.DefaultVersion, apiMinVersion))
+	m, err := middleware.NewVersionMiddleware("0.1omega2", api.DefaultVersion, api.MinSupportedAPIVersion)
+	if err != nil {
+		t.Fatal(err)
+	}
+	srv.UseMiddleware(*m)
 
 	req, _ := http.NewRequest(http.MethodGet, "/containers/json", nil)
 	resp := httptest.NewRecorder()
diff --git a/api/types/backend/backend.go b/api/types/backend/backend.go
index a4fb9d638af6f..cb965c25bee8b 100644
--- a/api/types/backend/backend.go
+++ b/api/types/backend/backend.go
@@ -18,7 +18,6 @@ type ContainerCreateConfig struct {
 	HostConfig       *container.HostConfig
 	NetworkingConfig *network.NetworkingConfig
 	Platform         *ocispec.Platform
-	AdjustCPUShares  bool
 }
 
 // ContainerRmConfig holds arguments for the container remove
@@ -90,7 +89,6 @@ type ContainerStatsConfig struct {
 	Stream    bool
 	OneShot   bool
 	OutStream io.Writer
-	Version   string
 }
 
 // ExecInspect holds information about a running process started
diff --git a/api/types/versions/README.md b/api/types/versions/README.md
deleted file mode 100644
index 1ef911edb0f9a..0000000000000
--- a/api/types/versions/README.md
+++ /dev/null
@@ -1,14 +0,0 @@
-# Legacy API type versions
-
-This package includes types for legacy API versions. The stable version of the API types live in `api/types/*.go`.
-
-Consider moving a type here when you need to keep backwards compatibility in the API. This legacy types are organized by the latest API version they appear in. For instance, types in the `v1p19` package are valid for API versions below or equal `1.19`. Types in the `v1p20` package are valid for the API version `1.20`, since the versions below that will use the legacy types in `v1p19`.
-
-## Package name conventions
-
-The package name convention is to use `v` as a prefix for the version number and `p`(patch) as a separator. We use this nomenclature due to a few restrictions in the Go package name convention:
-
-1. We cannot use `.` because it's interpreted by the language, think of `v1.20.CallFunction`.
-2. We cannot use `_` because golint complains about it. The code is actually valid, but it looks probably more weird: `v1_20.CallFunction`.
-
-For instance, if you want to modify a type that was available in the version `1.21` of the API but it will have different fields in the version `1.22`, you want to create a new package under `api/types/versions/v1p21`.
diff --git a/api/types/versions/v1p19/types.go b/api/types/versions/v1p19/types.go
deleted file mode 100644
index 58afe32da0aae..0000000000000
--- a/api/types/versions/v1p19/types.go
+++ /dev/null
@@ -1,35 +0,0 @@
-// Package v1p19 provides specific API types for the API version 1, patch 19.
-package v1p19 // import "github.com/docker/docker/api/types/versions/v1p19"
-
-import (
-	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/container"
-	"github.com/docker/docker/api/types/versions/v1p20"
-	"github.com/docker/go-connections/nat"
-)
-
-// ContainerJSON is a backcompatibility struct for APIs prior to 1.20.
-// Note this is not used by the Windows daemon.
-type ContainerJSON struct {
-	*types.ContainerJSONBase
-	Volumes         map[string]string
-	VolumesRW       map[string]bool
-	Config          *ContainerConfig
-	NetworkSettings *v1p20.NetworkSettings
-}
-
-// ContainerConfig is a backcompatibility struct for APIs prior to 1.20.
-type ContainerConfig struct {
-	*container.Config
-
-	MacAddress      string
-	NetworkDisabled bool
-	ExposedPorts    map[nat.Port]struct{}
-
-	// backward compatibility, they now live in HostConfig
-	VolumeDriver string
-	Memory       int64
-	MemorySwap   int64
-	CPUShares    int64  `json:"CpuShares"`
-	CPUSet       string `json:"Cpuset"`
-}
diff --git a/api/types/versions/v1p20/types.go b/api/types/versions/v1p20/types.go
deleted file mode 100644
index cc7277b1b4739..0000000000000
--- a/api/types/versions/v1p20/types.go
+++ /dev/null
@@ -1,40 +0,0 @@
-// Package v1p20 provides specific API types for the API version 1, patch 20.
-package v1p20 // import "github.com/docker/docker/api/types/versions/v1p20"
-
-import (
-	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/container"
-	"github.com/docker/go-connections/nat"
-)
-
-// ContainerJSON is a backcompatibility struct for the API 1.20
-type ContainerJSON struct {
-	*types.ContainerJSONBase
-	Mounts          []types.MountPoint
-	Config          *ContainerConfig
-	NetworkSettings *NetworkSettings
-}
-
-// ContainerConfig is a backcompatibility struct used in ContainerJSON for the API 1.20
-type ContainerConfig struct {
-	*container.Config
-
-	MacAddress      string
-	NetworkDisabled bool
-	ExposedPorts    map[nat.Port]struct{}
-
-	// backward compatibility, they now live in HostConfig
-	VolumeDriver string
-}
-
-// StatsJSON is a backcompatibility struct used in Stats for APIs prior to 1.21
-type StatsJSON struct {
-	types.Stats
-	Network types.NetworkStats `json:"network,omitempty"`
-}
-
-// NetworkSettings is a backward compatible struct for APIs prior to 1.21
-type NetworkSettings struct {
-	types.NetworkSettingsBase
-	types.DefaultNetworkSettings
-}
diff --git a/builder/builder.go b/builder/builder.go
index fc855f133d8e5..dff93cfac76e3 100644
--- a/builder/builder.go
+++ b/builder/builder.go
@@ -64,7 +64,7 @@ type ExecBackend interface {
 	// ContainerRm removes a container specified by `id`.
 	ContainerRm(name string, config *backend.ContainerRmConfig) error
 	// ContainerStart starts a new container
-	ContainerStart(ctx context.Context, containerID string, hostConfig *container.HostConfig, checkpoint string, checkpointDir string) error
+	ContainerStart(ctx context.Context, containerID string, checkpoint string, checkpointDir string) error
 	// ContainerWait stops processing until the given container is stopped.
 	ContainerWait(ctx context.Context, name string, condition containerpkg.WaitCondition) (<-chan containerpkg.StateStatus, error)
 }
diff --git a/builder/dockerfile/containerbackend.go b/builder/dockerfile/containerbackend.go
index 8986c1277a95a..c81923cbc6c2e 100644
--- a/builder/dockerfile/containerbackend.go
+++ b/builder/dockerfile/containerbackend.go
@@ -72,7 +72,7 @@ func (c *containerManager) Run(ctx context.Context, cID string, stdout, stderr i
 		}
 	}()
 
-	if err := c.backend.ContainerStart(ctx, cID, nil, "", ""); err != nil {
+	if err := c.backend.ContainerStart(ctx, cID, "", ""); err != nil {
 		close(finished)
 		logCancellationError(cancelErrCh, "error from ContainerStart: "+err.Error())
 		return err
diff --git a/builder/dockerfile/mockbackend_test.go b/builder/dockerfile/mockbackend_test.go
index e21e5b9ba5567..a5f6d3e73f42b 100644
--- a/builder/dockerfile/mockbackend_test.go
+++ b/builder/dockerfile/mockbackend_test.go
@@ -46,7 +46,7 @@ func (m *MockBackend) CommitBuildStep(ctx context.Context, c backend.CommitConfi
 	return "", nil
 }
 
-func (m *MockBackend) ContainerStart(ctx context.Context, containerID string, hostConfig *container.HostConfig, checkpoint string, checkpointDir string) error {
+func (m *MockBackend) ContainerStart(ctx context.Context, containerID string, checkpoint string, checkpointDir string) error {
 	return nil
 }
 
diff --git a/cmd/dockerd/daemon.go b/cmd/dockerd/daemon.go
index 9a8ffe0b0cc20..99c5aabbf860a 100644
--- a/cmd/dockerd/daemon.go
+++ b/cmd/dockerd/daemon.go
@@ -256,7 +256,10 @@ func (cli *DaemonCli) start(opts *daemonOptions) (err error) {
 	pluginStore := plugin.NewStore()
 
 	var apiServer apiserver.Server
-	cli.authzMiddleware = initMiddlewares(&apiServer, cli.Config, pluginStore)
+	cli.authzMiddleware, err = initMiddlewares(&apiServer, cli.Config, pluginStore)
+	if err != nil {
+		return errors.Wrap(err, "failed to start API server")
+	}
 
 	d, err := daemon.NewDaemon(ctx, cli.Config, pluginStore, cli.authzMiddleware)
 	if err != nil {
@@ -708,14 +711,15 @@ func (opts routerOptions) Build() []router.Router {
 	return routers
 }
 
-func initMiddlewares(s *apiserver.Server, cfg *config.Config, pluginStore plugingetter.PluginGetter) *authorization.Middleware {
-	v := dockerversion.Version
-
+func initMiddlewares(s *apiserver.Server, cfg *config.Config, pluginStore plugingetter.PluginGetter) (*authorization.Middleware, error) {
 	exp := middleware.NewExperimentalMiddleware(cfg.Experimental)
 	s.UseMiddleware(exp)
 
-	vm := middleware.NewVersionMiddleware(v, api.DefaultVersion, cfg.MinAPIVersion)
-	s.UseMiddleware(vm)
+	vm, err := middleware.NewVersionMiddleware(dockerversion.Version, api.DefaultVersion, cfg.MinAPIVersion)
+	if err != nil {
+		return nil, err
+	}
+	s.UseMiddleware(*vm)
 
 	if cfg.CorsHeaders != "" {
 		c := middleware.NewCORSMiddleware(cfg.CorsHeaders)
@@ -724,7 +728,7 @@ func initMiddlewares(s *apiserver.Server, cfg *config.Config, pluginStore plugin
 
 	authzMiddleware := authorization.NewMiddleware(cfg.AuthorizationPlugins, pluginStore)
 	s.UseMiddleware(authzMiddleware)
-	return authzMiddleware
+	return authzMiddleware, nil
 }
 
 func (cli *DaemonCli) getContainerdDaemonOpts() ([]supervisor.DaemonOpt, error) {
diff --git a/daemon/archive.go b/daemon/archive.go
index 4be02b25c627e..65a67ffcc2b8b 100644
--- a/daemon/archive.go
+++ b/daemon/archive.go
@@ -8,25 +8,6 @@ import (
 	"github.com/docker/docker/errdefs"
 )
 
-// ContainerCopy performs a deprecated operation of archiving the resource at
-// the specified path in the container identified by the given name.
-func (daemon *Daemon) ContainerCopy(name string, res string) (io.ReadCloser, error) {
-	ctr, err := daemon.GetContainer(name)
-	if err != nil {
-		return nil, err
-	}
-
-	data, err := daemon.containerCopy(ctr, res)
-	if err == nil {
-		return data, nil
-	}
-
-	if os.IsNotExist(err) {
-		return nil, containerFileNotFound{res, name}
-	}
-	return nil, errdefs.System(err)
-}
-
 // ContainerStatPath stats the filesystem resource at the specified path in the
 // container identified by the given name.
 func (daemon *Daemon) ContainerStatPath(name string, path string) (stat *types.ContainerPathStat, err error) {
diff --git a/daemon/archive_unix.go b/daemon/archive_unix.go
index 837e671c2cf73..cbbf9c5f8a5bb 100644
--- a/daemon/archive_unix.go
+++ b/daemon/archive_unix.go
@@ -161,55 +161,6 @@ func (daemon *Daemon) containerExtractToDir(container *container.Container, path
 	return nil
 }
 
-func (daemon *Daemon) containerCopy(container *container.Container, resource string) (rc io.ReadCloser, err error) {
-	container.Lock()
-
-	defer func() {
-		if err != nil {
-			// Wait to unlock the container until the archive is fully read
-			// (see the ReadCloseWrapper func below) or if there is an error
-			// before that occurs.
-			container.Unlock()
-		}
-	}()
-
-	cfs, err := daemon.openContainerFS(container)
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		if err != nil {
-			cfs.Close()
-		}
-	}()
-
-	err = cfs.RunInFS(context.TODO(), func() error {
-		_, err := os.Stat(resource)
-		return err
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	tb, err := archive.NewTarballer(resource, &archive.TarOptions{
-		Compression: archive.Uncompressed,
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	cfs.GoInFS(context.TODO(), tb.Do)
-	archv := tb.Reader()
-	reader := ioutils.NewReadCloserWrapper(archv, func() error {
-		err := archv.Close()
-		_ = cfs.Close()
-		container.Unlock()
-		return err
-	})
-	daemon.LogContainerEvent(container, events.ActionCopy)
-	return reader, nil
-}
-
 // checkIfPathIsInAVolume checks if the path is in a volume. If it is, it
 // cannot be in a read-only volume. If it  is not in a volume, the container
 // cannot be configured with a read-only rootfs.
diff --git a/daemon/cluster/executor/backend.go b/daemon/cluster/executor/backend.go
index 855dc14e483eb..6362ca31e18fd 100644
--- a/daemon/cluster/executor/backend.go
+++ b/daemon/cluster/executor/backend.go
@@ -38,7 +38,7 @@ type Backend interface {
 	SetupIngress(clustertypes.NetworkCreateRequest, string) (<-chan struct{}, error)
 	ReleaseIngress() (<-chan struct{}, error)
 	CreateManagedContainer(ctx context.Context, config backend.ContainerCreateConfig) (container.CreateResponse, error)
-	ContainerStart(ctx context.Context, name string, hostConfig *container.HostConfig, checkpoint string, checkpointDir string) error
+	ContainerStart(ctx context.Context, name string, checkpoint string, checkpointDir string) error
 	ContainerStop(ctx context.Context, name string, config container.StopOptions) error
 	ContainerLogs(ctx context.Context, name string, config *container.LogsOptions) (msgs <-chan *backend.LogMessage, tty bool, err error)
 	ConnectContainerToNetwork(containerName, networkName string, endpointConfig *network.EndpointSettings) error
diff --git a/daemon/cluster/executor/container/adapter.go b/daemon/cluster/executor/container/adapter.go
index a6f04fae7a3d8..7360031ffa7cd 100644
--- a/daemon/cluster/executor/container/adapter.go
+++ b/daemon/cluster/executor/container/adapter.go
@@ -347,7 +347,7 @@ func (c *containerAdapter) start(ctx context.Context) error {
 		return err
 	}
 
-	return c.backend.ContainerStart(ctx, c.container.name(), nil, "", "")
+	return c.backend.ContainerStart(ctx, c.container.name(), "", "")
 }
 
 func (c *containerAdapter) inspect(ctx context.Context) (types.ContainerJSON, error) {
diff --git a/daemon/config/config.go b/daemon/config/config.go
index 6e01495b08e2f..a72fba044df63 100644
--- a/daemon/config/config.go
+++ b/daemon/config/config.go
@@ -56,9 +56,9 @@ const (
 	DefaultPluginNamespace = "plugins.moby"
 	// defaultMinAPIVersion is the minimum API version supported by the API.
 	// This version can be overridden through the "DOCKER_MIN_API_VERSION"
-	// environment variable. The minimum allowed version is determined
-	// by [minAPIVersion].
-	defaultMinAPIVersion = "1.24"
+	// environment variable. It currently defaults to the minimum API version
+	// supported by the API server.
+	defaultMinAPIVersion = api.MinSupportedAPIVersion
 	// SeccompProfileDefault is the built-in default seccomp profile.
 	SeccompProfileDefault = "builtin"
 	// SeccompProfileUnconfined is a special profile name for seccomp to use an
@@ -610,8 +610,8 @@ func ValidateMinAPIVersion(ver string) error {
 	if strings.EqualFold(ver[0:1], "v") {
 		return errors.New(`API version must be provided without "v" prefix`)
 	}
-	if versions.LessThan(ver, minAPIVersion) {
-		return errors.Errorf(`minimum supported API version is %s: %s`, minAPIVersion, ver)
+	if versions.LessThan(ver, defaultMinAPIVersion) {
+		return errors.Errorf(`minimum supported API version is %s: %s`, defaultMinAPIVersion, ver)
 	}
 	if versions.GreaterThan(ver, api.DefaultVersion) {
 		return errors.Errorf(`maximum supported API version is %s: %s`, api.DefaultVersion, ver)
diff --git a/daemon/config/config_linux.go b/daemon/config/config_linux.go
index 2c2aabafd666d..986677a0acad1 100644
--- a/daemon/config/config_linux.go
+++ b/daemon/config/config_linux.go
@@ -33,9 +33,6 @@ const (
 	// OCI runtime being shipped with the docker daemon package.
 	StockRuntimeName = "runc"
 
-	// minAPIVersion represents Minimum REST API version supported
-	minAPIVersion = "1.12"
-
 	// userlandProxyBinary is the name of the userland-proxy binary.
 	// In rootless-mode, [rootless.RootlessKitDockerProxyBinary] is used instead.
 	userlandProxyBinary = "docker-proxy"
diff --git a/daemon/config/config_windows.go b/daemon/config/config_windows.go
index 825b150f85842..05e185da8851b 100644
--- a/daemon/config/config_windows.go
+++ b/daemon/config/config_windows.go
@@ -13,13 +13,6 @@ const (
 	// default value. On Windows keep this empty so the value is auto-detected
 	// based on other options.
 	StockRuntimeName = ""
-
-	// minAPIVersion represents Minimum REST API version supported
-	// Technically the first daemon API version released on Windows is v1.25 in
-	// engine version 1.13. However, some clients are explicitly using downlevel
-	// APIs (e.g. docker-compose v2.1 file format) and that is just too restrictive.
-	// Hence also allowing 1.24 on Windows.
-	minAPIVersion string = "1.24"
 )
 
 // BridgeConfig is meant to store all the parameters for both the bridge driver and the default bridge network. On
diff --git a/daemon/create.go b/daemon/create.go
index aa063b60aa5ef..4f8da469b79f8 100644
--- a/daemon/create.go
+++ b/daemon/create.go
@@ -108,7 +108,7 @@ func (daemon *Daemon) containerCreate(ctx context.Context, daemonCfg *configStor
 	if opts.params.HostConfig == nil {
 		opts.params.HostConfig = &containertypes.HostConfig{}
 	}
-	err = daemon.adaptContainerSettings(&daemonCfg.Config, opts.params.HostConfig, opts.params.AdjustCPUShares)
+	err = daemon.adaptContainerSettings(&daemonCfg.Config, opts.params.HostConfig)
 	if err != nil {
 		return containertypes.CreateResponse{Warnings: warnings}, errdefs.InvalidParameter(err)
 	}
diff --git a/daemon/daemon_unix.go b/daemon/daemon_unix.go
index 1143dda063a50..120f514ef712c 100644
--- a/daemon/daemon_unix.go
+++ b/daemon/daemon_unix.go
@@ -54,9 +54,16 @@ import (
 const (
 	isWindows = false
 
+	// These values were used to adjust the CPU-shares for older API versions,
+	// but were not used for validation.
+	//
+	// TODO(thaJeztah): validate min/max values for CPU-shares, similar to Windows: https://github.com/moby/moby/issues/47340
+	// https://github.com/moby/moby/blob/27e85c7b6885c2d21ae90791136d9aba78b83d01/daemon/daemon_windows.go#L97-L99
+	//
 	// See https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/tree/kernel/sched/sched.h?id=8cd9234c64c584432f6992fe944ca9e46ca8ea76#n269
-	linuxMinCPUShares = 2
-	linuxMaxCPUShares = 262144
+	// linuxMinCPUShares = 2
+	// linuxMaxCPUShares = 262144
+
 	// It's not kernel limit, we want this 6M limit to account for overhead during startup, and to supply a reasonable functional container
 	linuxMinMemory = 6291456
 	// constants for remapped root settings
@@ -306,17 +313,7 @@ func adjustParallelLimit(n int, limit int) int {
 
 // adaptContainerSettings is called during container creation to modify any
 // settings necessary in the HostConfig structure.
-func (daemon *Daemon) adaptContainerSettings(daemonCfg *config.Config, hostConfig *containertypes.HostConfig, adjustCPUShares bool) error {
-	if adjustCPUShares && hostConfig.CPUShares > 0 {
-		// Handle unsupported CPUShares
-		if hostConfig.CPUShares < linuxMinCPUShares {
-			log.G(context.TODO()).Warnf("Changing requested CPUShares of %d to minimum allowed of %d", hostConfig.CPUShares, linuxMinCPUShares)
-			hostConfig.CPUShares = linuxMinCPUShares
-		} else if hostConfig.CPUShares > linuxMaxCPUShares {
-			log.G(context.TODO()).Warnf("Changing requested CPUShares of %d to maximum allowed of %d", hostConfig.CPUShares, linuxMaxCPUShares)
-			hostConfig.CPUShares = linuxMaxCPUShares
-		}
-	}
+func (daemon *Daemon) adaptContainerSettings(daemonCfg *config.Config, hostConfig *containertypes.HostConfig) error {
 	if hostConfig.Memory > 0 && hostConfig.MemorySwap == 0 {
 		// By default, MemorySwap is set to twice the size of Memory.
 		hostConfig.MemorySwap = hostConfig.Memory * 2
diff --git a/daemon/daemon_unix_test.go b/daemon/daemon_unix_test.go
index 37dab2dd9b701..e681eac8925a4 100644
--- a/daemon/daemon_unix_test.go
+++ b/daemon/daemon_unix_test.go
@@ -57,87 +57,6 @@ func TestAdjustSharedNamespaceContainerName(t *testing.T) {
 	}
 }
 
-// Unix test as uses settings which are not available on Windows
-func TestAdjustCPUShares(t *testing.T) {
-	tmp, err := os.MkdirTemp("", "docker-daemon-unix-test-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmp)
-	daemon := &Daemon{
-		repository: tmp,
-		root:       tmp,
-	}
-	cfg := &config.Config{}
-	muteLogs(t)
-
-	hostConfig := &containertypes.HostConfig{
-		Resources: containertypes.Resources{CPUShares: linuxMinCPUShares - 1},
-	}
-	daemon.adaptContainerSettings(cfg, hostConfig, true)
-	if hostConfig.CPUShares != linuxMinCPUShares {
-		t.Errorf("Expected CPUShares to be %d", linuxMinCPUShares)
-	}
-
-	hostConfig.CPUShares = linuxMaxCPUShares + 1
-	daemon.adaptContainerSettings(cfg, hostConfig, true)
-	if hostConfig.CPUShares != linuxMaxCPUShares {
-		t.Errorf("Expected CPUShares to be %d", linuxMaxCPUShares)
-	}
-
-	hostConfig.CPUShares = 0
-	daemon.adaptContainerSettings(cfg, hostConfig, true)
-	if hostConfig.CPUShares != 0 {
-		t.Error("Expected CPUShares to be unchanged")
-	}
-
-	hostConfig.CPUShares = 1024
-	daemon.adaptContainerSettings(cfg, hostConfig, true)
-	if hostConfig.CPUShares != 1024 {
-		t.Error("Expected CPUShares to be unchanged")
-	}
-}
-
-// Unix test as uses settings which are not available on Windows
-func TestAdjustCPUSharesNoAdjustment(t *testing.T) {
-	tmp, err := os.MkdirTemp("", "docker-daemon-unix-test-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmp)
-	daemon := &Daemon{
-		repository: tmp,
-		root:       tmp,
-	}
-	cfg := &config.Config{}
-
-	hostConfig := &containertypes.HostConfig{
-		Resources: containertypes.Resources{CPUShares: linuxMinCPUShares - 1},
-	}
-	daemon.adaptContainerSettings(cfg, hostConfig, false)
-	if hostConfig.CPUShares != linuxMinCPUShares-1 {
-		t.Errorf("Expected CPUShares to be %d", linuxMinCPUShares-1)
-	}
-
-	hostConfig.CPUShares = linuxMaxCPUShares + 1
-	daemon.adaptContainerSettings(cfg, hostConfig, false)
-	if hostConfig.CPUShares != linuxMaxCPUShares+1 {
-		t.Errorf("Expected CPUShares to be %d", linuxMaxCPUShares+1)
-	}
-
-	hostConfig.CPUShares = 0
-	daemon.adaptContainerSettings(cfg, hostConfig, false)
-	if hostConfig.CPUShares != 0 {
-		t.Error("Expected CPUShares to be unchanged")
-	}
-
-	hostConfig.CPUShares = 1024
-	daemon.adaptContainerSettings(cfg, hostConfig, false)
-	if hostConfig.CPUShares != 1024 {
-		t.Error("Expected CPUShares to be unchanged")
-	}
-}
-
 // Unix test as uses settings which are not available on Windows
 func TestParseSecurityOptWithDeprecatedColon(t *testing.T) {
 	opts := &container.SecurityOptions{}
diff --git a/daemon/daemon_windows.go b/daemon/daemon_windows.go
index 1b03e4f5a7115..54bc6d4941f59 100644
--- a/daemon/daemon_windows.go
+++ b/daemon/daemon_windows.go
@@ -66,7 +66,7 @@ func setupInitLayer(idMapping idtools.IdentityMapping) func(string) error {
 
 // adaptContainerSettings is called during container creation to modify any
 // settings necessary in the HostConfig structure.
-func (daemon *Daemon) adaptContainerSettings(daemonCfg *config.Config, hostConfig *containertypes.HostConfig, adjustCPUShares bool) error {
+func (daemon *Daemon) adaptContainerSettings(daemonCfg *config.Config, hostConfig *containertypes.HostConfig) error {
 	return nil
 }
 
diff --git a/daemon/inspect.go b/daemon/inspect.go
index db2d0f7d65e07..62c7896ac3d01 100644
--- a/daemon/inspect.go
+++ b/daemon/inspect.go
@@ -14,7 +14,6 @@ import (
 	containertypes "github.com/docker/docker/api/types/container"
 	networktypes "github.com/docker/docker/api/types/network"
 	"github.com/docker/docker/api/types/versions"
-	"github.com/docker/docker/api/types/versions/v1p20"
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/daemon/config"
 	"github.com/docker/docker/daemon/network"
@@ -29,10 +28,6 @@ import (
 // there is an error getting the data.
 func (daemon *Daemon) ContainerInspect(ctx context.Context, name string, size bool, version string) (interface{}, error) {
 	switch {
-	case versions.LessThan(version, "1.20"):
-		return daemon.containerInspectPre120(ctx, name)
-	case versions.Equal(version, "1.20"):
-		return daemon.containerInspect120(name)
 	case versions.LessThan(version, "1.45"):
 		ctr, err := daemon.ContainerInspectCurrent(ctx, name, size)
 		if err != nil {
@@ -117,35 +112,6 @@ func (daemon *Daemon) ContainerInspectCurrent(ctx context.Context, name string,
 	}, nil
 }
 
-// containerInspect120 serializes the master version of a container into a json type.
-func (daemon *Daemon) containerInspect120(name string) (*v1p20.ContainerJSON, error) {
-	ctr, err := daemon.GetContainer(name)
-	if err != nil {
-		return nil, err
-	}
-
-	ctr.Lock()
-	defer ctr.Unlock()
-
-	base, err := daemon.getInspectData(&daemon.config().Config, ctr)
-	if err != nil {
-		return nil, err
-	}
-
-	return &v1p20.ContainerJSON{
-		ContainerJSONBase: base,
-		Mounts:            ctr.GetMountPoints(),
-		Config: &v1p20.ContainerConfig{
-			Config:          ctr.Config,
-			MacAddress:      ctr.Config.MacAddress, //nolint:staticcheck // ignore SA1019: field is deprecated, but still used on API < v1.44.
-			NetworkDisabled: ctr.Config.NetworkDisabled,
-			ExposedPorts:    ctr.Config.ExposedPorts,
-			VolumeDriver:    ctr.HostConfig.VolumeDriver,
-		},
-		NetworkSettings: daemon.getBackwardsCompatibleNetworkSettings(ctr.NetworkSettings),
-	}, nil
-}
-
 func (daemon *Daemon) getInspectData(daemonCfg *config.Config, container *container.Container) (*types.ContainerJSONBase, error) {
 	// make a copy to play with
 	hostConfig := *container.HostConfig
@@ -283,25 +249,6 @@ func (daemon *Daemon) ContainerExecInspect(id string) (*backend.ExecInspect, err
 	}, nil
 }
 
-func (daemon *Daemon) getBackwardsCompatibleNetworkSettings(settings *network.Settings) *v1p20.NetworkSettings {
-	result := &v1p20.NetworkSettings{
-		NetworkSettingsBase: types.NetworkSettingsBase{
-			Bridge:                 settings.Bridge,
-			SandboxID:              settings.SandboxID,
-			SandboxKey:             settings.SandboxKey,
-			HairpinMode:            settings.HairpinMode,
-			LinkLocalIPv6Address:   settings.LinkLocalIPv6Address,
-			LinkLocalIPv6PrefixLen: settings.LinkLocalIPv6PrefixLen,
-			Ports:                  settings.Ports,
-			SecondaryIPAddresses:   settings.SecondaryIPAddresses,
-			SecondaryIPv6Addresses: settings.SecondaryIPv6Addresses,
-		},
-		DefaultNetworkSettings: daemon.getDefaultNetworkSettings(settings.Networks),
-	}
-
-	return result
-}
-
 // getDefaultNetworkSettings creates the deprecated structure that holds the information
 // about the bridge network for a container.
 func (daemon *Daemon) getDefaultNetworkSettings(networks map[string]*network.EndpointSettings) types.DefaultNetworkSettings {
diff --git a/daemon/inspect_linux.go b/daemon/inspect_linux.go
index bcfaf105ed264..5f8606b38a5df 100644
--- a/daemon/inspect_linux.go
+++ b/daemon/inspect_linux.go
@@ -1,11 +1,8 @@
 package daemon // import "github.com/docker/docker/daemon"
 
 import (
-	"context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
-	"github.com/docker/docker/api/types/versions/v1p19"
 	"github.com/docker/docker/container"
 )
 
@@ -19,47 +16,6 @@ func setPlatformSpecificContainerFields(container *container.Container, contJSON
 	return contJSONBase
 }
 
-// containerInspectPre120 gets containers for pre 1.20 APIs.
-func (daemon *Daemon) containerInspectPre120(ctx context.Context, name string) (*v1p19.ContainerJSON, error) {
-	ctr, err := daemon.GetContainer(name)
-	if err != nil {
-		return nil, err
-	}
-
-	ctr.Lock()
-	defer ctr.Unlock()
-
-	base, err := daemon.getInspectData(&daemon.config().Config, ctr)
-	if err != nil {
-		return nil, err
-	}
-
-	volumes := make(map[string]string)
-	volumesRW := make(map[string]bool)
-	for _, m := range ctr.MountPoints {
-		volumes[m.Destination] = m.Path()
-		volumesRW[m.Destination] = m.RW
-	}
-
-	return &v1p19.ContainerJSON{
-		ContainerJSONBase: base,
-		Volumes:           volumes,
-		VolumesRW:         volumesRW,
-		Config: &v1p19.ContainerConfig{
-			Config:          ctr.Config,
-			MacAddress:      ctr.Config.MacAddress, //nolint:staticcheck // ignore SA1019: field is deprecated, but still used on API < v1.44.
-			NetworkDisabled: ctr.Config.NetworkDisabled,
-			ExposedPorts:    ctr.Config.ExposedPorts,
-			VolumeDriver:    ctr.HostConfig.VolumeDriver,
-			Memory:          ctr.HostConfig.Memory,
-			MemorySwap:      ctr.HostConfig.MemorySwap,
-			CPUShares:       ctr.HostConfig.CPUShares,
-			CPUSet:          ctr.HostConfig.CpusetCpus,
-		},
-		NetworkSettings: daemon.getBackwardsCompatibleNetworkSettings(ctr.NetworkSettings),
-	}, nil
-}
-
 func inspectExecProcessConfig(e *container.ExecConfig) *backend.ExecProcessConfig {
 	return &backend.ExecProcessConfig{
 		Tty:        e.Tty,
diff --git a/daemon/inspect_windows.go b/daemon/inspect_windows.go
index c43112f853919..95aa772c65757 100644
--- a/daemon/inspect_windows.go
+++ b/daemon/inspect_windows.go
@@ -1,8 +1,6 @@
 package daemon // import "github.com/docker/docker/daemon"
 
 import (
-	"context"
-
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
 	"github.com/docker/docker/container"
@@ -13,11 +11,6 @@ func setPlatformSpecificContainerFields(container *container.Container, contJSON
 	return contJSONBase
 }
 
-// containerInspectPre120 get containers for pre 1.20 APIs.
-func (daemon *Daemon) containerInspectPre120(ctx context.Context, name string) (*types.ContainerJSON, error) {
-	return daemon.ContainerInspectCurrent(ctx, name, false)
-}
-
 func inspectExecProcessConfig(e *container.ExecConfig) *backend.ExecProcessConfig {
 	return &backend.ExecProcessConfig{
 		Tty:        e.Tty,
diff --git a/daemon/start.go b/daemon/start.go
index 516c069958a65..b967947af2cec 100644
--- a/daemon/start.go
+++ b/daemon/start.go
@@ -2,12 +2,10 @@ package daemon // import "github.com/docker/docker/daemon"
 
 import (
 	"context"
-	"runtime"
 	"time"
 
 	"github.com/containerd/log"
 	"github.com/docker/docker/api/types/backend"
-	containertypes "github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/events"
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/errdefs"
@@ -41,7 +39,7 @@ func validateState(ctr *container.Container) error {
 }
 
 // ContainerStart starts a container.
-func (daemon *Daemon) ContainerStart(ctx context.Context, name string, hostConfig *containertypes.HostConfig, checkpoint string, checkpointDir string) error {
+func (daemon *Daemon) ContainerStart(ctx context.Context, name string, checkpoint string, checkpointDir string) error {
 	daemonCfg := daemon.config()
 	if checkpoint != "" && !daemonCfg.Experimental {
 		return errdefs.InvalidParameter(errors.New("checkpoint is only supported in experimental mode"))
@@ -55,51 +53,12 @@ func (daemon *Daemon) ContainerStart(ctx context.Context, name string, hostConfi
 		return err
 	}
 
-	// Windows does not have the backwards compatibility issue here.
-	if runtime.GOOS != "windows" {
-		// This is kept for backward compatibility - hostconfig should be passed when
-		// creating a container, not during start.
-		if hostConfig != nil {
-			log.G(ctx).Warn("DEPRECATED: Setting host configuration options when the container starts is deprecated and has been removed in Docker 1.12")
-			oldNetworkMode := ctr.HostConfig.NetworkMode
-			if err := daemon.setSecurityOptions(&daemonCfg.Config, ctr, hostConfig); err != nil {
-				return errdefs.InvalidParameter(err)
-			}
-			if err := daemon.mergeAndVerifyLogConfig(&hostConfig.LogConfig); err != nil {
-				return errdefs.InvalidParameter(err)
-			}
-			if err := daemon.setHostConfig(ctr, hostConfig); err != nil {
-				return errdefs.InvalidParameter(err)
-			}
-			newNetworkMode := ctr.HostConfig.NetworkMode
-			if string(oldNetworkMode) != string(newNetworkMode) {
-				// if user has change the network mode on starting, clean up the
-				// old networks. It is a deprecated feature and has been removed in Docker 1.12
-				ctr.NetworkSettings.Networks = nil
-			}
-			if err := ctr.CheckpointTo(daemon.containersReplica); err != nil {
-				return errdefs.System(err)
-			}
-			ctr.InitDNSHostConfig()
-		}
-	} else {
-		if hostConfig != nil {
-			return errdefs.InvalidParameter(errors.New("Supplying a hostconfig on start is not supported. It should be supplied on create"))
-		}
-	}
-
 	// check if hostConfig is in line with the current system settings.
-	// It may happen cgroups are umounted or the like.
+	// It may happen cgroups are unmounted or the like.
 	if _, err = daemon.verifyContainerSettings(daemonCfg, ctr.HostConfig, nil, false); err != nil {
 		return errdefs.InvalidParameter(err)
 	}
-	// Adapt for old containers in case we have updates in this function and
-	// old containers never have chance to call the new function in create stage.
-	if hostConfig != nil {
-		if err := daemon.adaptContainerSettings(&daemonCfg.Config, ctr.HostConfig, false); err != nil {
-			return errdefs.InvalidParameter(err)
-		}
-	}
+
 	return daemon.containerStart(ctx, daemonCfg, ctr, checkpoint, checkpointDir, true)
 }
 
diff --git a/daemon/stats.go b/daemon/stats.go
index 342d7a9c66cd4..5dcd6121d4400 100644
--- a/daemon/stats.go
+++ b/daemon/stats.go
@@ -10,8 +10,6 @@ import (
 	"github.com/containerd/log"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
-	"github.com/docker/docker/api/types/versions"
-	"github.com/docker/docker/api/types/versions/v1p20"
 	"github.com/docker/docker/container"
 	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/pkg/ioutils"
@@ -20,13 +18,6 @@ import (
 // ContainerStats writes information about the container to the stream
 // given in the config object.
 func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, config *backend.ContainerStatsConfig) error {
-	// Engine API version (used for backwards compatibility)
-	apiVersion := config.Version
-
-	if isWindows && versions.LessThan(apiVersion, "1.21") {
-		return errors.New("API versions pre v1.21 do not support stats on Windows")
-	}
-
 	ctr, err := daemon.GetContainer(prefixOrName)
 	if err != nil {
 		return err
@@ -87,46 +78,7 @@ func (daemon *Daemon) ContainerStats(ctx context.Context, prefixOrName string, c
 				return nil
 			}
 
-			var statsJSON interface{}
-			statsJSONPost120 := getStatJSON(v)
-			if versions.LessThan(apiVersion, "1.21") {
-				var (
-					rxBytes   uint64
-					rxPackets uint64
-					rxErrors  uint64
-					rxDropped uint64
-					txBytes   uint64
-					txPackets uint64
-					txErrors  uint64
-					txDropped uint64
-				)
-				for _, v := range statsJSONPost120.Networks {
-					rxBytes += v.RxBytes
-					rxPackets += v.RxPackets
-					rxErrors += v.RxErrors
-					rxDropped += v.RxDropped
-					txBytes += v.TxBytes
-					txPackets += v.TxPackets
-					txErrors += v.TxErrors
-					txDropped += v.TxDropped
-				}
-				statsJSON = &v1p20.StatsJSON{
-					Stats: statsJSONPost120.Stats,
-					Network: types.NetworkStats{
-						RxBytes:   rxBytes,
-						RxPackets: rxPackets,
-						RxErrors:  rxErrors,
-						RxDropped: rxDropped,
-						TxBytes:   txBytes,
-						TxPackets: txPackets,
-						TxErrors:  txErrors,
-						TxDropped: txDropped,
-					},
-				}
-			} else {
-				statsJSON = statsJSONPost120
-			}
-
+			statsJSON := getStatJSON(v)
 			if !config.Stream && noStreamFirstFrame {
 				// prime the cpu stats so they aren't 0 in the final output
 				noStreamFirstFrame = false
diff --git a/hack/make/.integration-daemon-start b/hack/make/.integration-daemon-start
index 503425ae2e1fd..cf8002afba0dd 100644
--- a/hack/make/.integration-daemon-start
+++ b/hack/make/.integration-daemon-start
@@ -46,9 +46,6 @@ export DOCKER_ALLOW_SCHEMA1_PUSH_DONOTUSE=1
 export DOCKER_GRAPHDRIVER=${DOCKER_GRAPHDRIVER:-vfs}
 export DOCKER_USERLANDPROXY=${DOCKER_USERLANDPROXY:-true}
 
-# Allow testing old API versions
-export DOCKER_MIN_API_VERSION=1.12
-
 # example usage: DOCKER_STORAGE_OPTS="dm.basesize=20G,dm.loopdatasize=200G"
 storage_params=""
 if [ -n "$DOCKER_STORAGE_OPTS" ]; then
diff --git a/integration-cli/docker_api_containers_test.go b/integration-cli/docker_api_containers_test.go
index c3839aad66551..52fb611d1f508 100644
--- a/integration-cli/docker_api_containers_test.go
+++ b/integration-cli/docker_api_containers_test.go
@@ -958,81 +958,6 @@ func (s *DockerAPISuite) TestContainerAPICopyNotExistsAnyMore(c *testing.T) {
 	assert.Equal(c, res.StatusCode, http.StatusNotFound)
 }
 
-func (s *DockerAPISuite) TestContainerAPICopyPre124(c *testing.T) {
-	testRequires(c, DaemonIsLinux) // Windows only supports 1.25 or later
-	const name = "test-container-api-copy"
-	cli.DockerCmd(c, "run", "--name", name, "busybox", "touch", "/test.txt")
-
-	postData := types.CopyConfig{
-		Resource: "/test.txt",
-	}
-
-	res, body, err := request.Post(testutil.GetContext(c), "/v1.23/containers/"+name+"/copy", request.JSONBody(postData))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusOK)
-
-	found := false
-	for tarReader := tar.NewReader(body); ; {
-		h, err := tarReader.Next()
-		if err != nil {
-			if err == io.EOF {
-				break
-			}
-			c.Fatal(err)
-		}
-		if h.Name == "test.txt" {
-			found = true
-			break
-		}
-	}
-	assert.Assert(c, found)
-}
-
-func (s *DockerAPISuite) TestContainerAPICopyResourcePathEmptyPre124(c *testing.T) {
-	testRequires(c, DaemonIsLinux) // Windows only supports 1.25 or later
-	const name = "test-container-api-copy-resource-empty"
-	cli.DockerCmd(c, "run", "--name", name, "busybox", "touch", "/test.txt")
-
-	postData := types.CopyConfig{
-		Resource: "",
-	}
-
-	res, body, err := request.Post(testutil.GetContext(c), "/v1.23/containers/"+name+"/copy", request.JSONBody(postData))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusBadRequest)
-	b, err := request.ReadBody(body)
-	assert.NilError(c, err)
-	assert.Assert(c, is.Regexp("^Path cannot be empty\n$", string(b)))
-}
-
-func (s *DockerAPISuite) TestContainerAPICopyResourcePathNotFoundPre124(c *testing.T) {
-	testRequires(c, DaemonIsLinux) // Windows only supports 1.25 or later
-	const name = "test-container-api-copy-resource-not-found"
-	cli.DockerCmd(c, "run", "--name", name, "busybox")
-
-	postData := types.CopyConfig{
-		Resource: "/notexist",
-	}
-
-	res, body, err := request.Post(testutil.GetContext(c), "/v1.23/containers/"+name+"/copy", request.JSONBody(postData))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNotFound)
-	b, err := request.ReadBody(body)
-	assert.NilError(c, err)
-	assert.Assert(c, is.Regexp("^Could not find the file /notexist in container "+name+"\n$", string(b)))
-}
-
-func (s *DockerAPISuite) TestContainerAPICopyContainerNotFoundPr124(c *testing.T) {
-	testRequires(c, DaemonIsLinux) // Windows only supports 1.25 or later
-	postData := types.CopyConfig{
-		Resource: "/something",
-	}
-
-	res, _, err := request.Post(testutil.GetContext(c), "/v1.23/containers/notexists/copy", request.JSONBody(postData))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNotFound)
-}
-
 func (s *DockerAPISuite) TestContainerAPIDelete(c *testing.T) {
 	id := runSleepingContainer(c)
 	cli.WaitRun(c, id)
@@ -1251,20 +1176,6 @@ func (s *DockerAPISuite) TestPostContainersCreateWithStringOrSliceCapAddDrop(c *
 	assert.NilError(c, err)
 }
 
-// #14915
-func (s *DockerAPISuite) TestContainerAPICreateNoHostConfig118(c *testing.T) {
-	testRequires(c, DaemonIsLinux) // Windows only support 1.25 or later
-	config := container.Config{
-		Image: "busybox",
-	}
-
-	apiClient, err := client.NewClientWithOpts(client.FromEnv, client.WithVersion("v1.18"))
-	assert.NilError(c, err)
-
-	_, err = apiClient.ContainerCreate(testutil.GetContext(c), &config, &container.HostConfig{}, &network.NetworkingConfig{}, nil, "")
-	assert.NilError(c, err)
-}
-
 // Ensure an error occurs when you have a container read-only rootfs but you
 // extract an archive to a symlink in a writable volume which points to a
 // directory outside of the volume.
diff --git a/integration-cli/docker_api_exec_test.go b/integration-cli/docker_api_exec_test.go
index f9612fc66704c..612ef292b15bf 100644
--- a/integration-cli/docker_api_exec_test.go
+++ b/integration-cli/docker_api_exec_test.go
@@ -109,20 +109,6 @@ func (s *DockerAPISuite) TestExecAPIStartEnsureHeaders(c *testing.T) {
 	assert.Assert(c, resp.Header.Get("Server") != "")
 }
 
-func (s *DockerAPISuite) TestExecAPIStartBackwardsCompatible(c *testing.T) {
-	testRequires(c, DaemonIsLinux) // Windows only supports 1.25 or later
-	runSleepingContainer(c, "-d", "--name", "test")
-	id := createExec(c, "test")
-
-	resp, body, err := request.Post(testutil.GetContext(c), fmt.Sprintf("/v1.20/exec/%s/start", id), request.RawString(`{"Detach": true}`), request.ContentType("text/plain"))
-	assert.NilError(c, err)
-
-	b, err := request.ReadBody(body)
-	comment := fmt.Sprintf("response body: %s", b)
-	assert.NilError(c, err, comment)
-	assert.Equal(c, resp.StatusCode, http.StatusOK, comment)
-}
-
 // #19362
 func (s *DockerAPISuite) TestExecAPIStartMultipleTimesError(c *testing.T) {
 	runSleepingContainer(c, "-d", "--name", "test")
diff --git a/integration-cli/docker_api_inspect_test.go b/integration-cli/docker_api_inspect_test.go
index e058e7f64a5e0..5a3c160f7d299 100644
--- a/integration-cli/docker_api_inspect_test.go
+++ b/integration-cli/docker_api_inspect_test.go
@@ -6,7 +6,6 @@ import (
 	"testing"
 
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/versions/v1p20"
 	"github.com/docker/docker/client"
 	"github.com/docker/docker/integration-cli/cli"
 	"github.com/docker/docker/testutil"
@@ -21,26 +20,15 @@ func (s *DockerAPISuite) TestInspectAPIContainerResponse(c *testing.T) {
 	keysBase := []string{
 		"Id", "State", "Created", "Path", "Args", "Config", "Image", "NetworkSettings",
 		"ResolvConfPath", "HostnamePath", "HostsPath", "LogPath", "Name", "Driver", "MountLabel", "ProcessLabel", "GraphDriver",
+		"Mounts",
 	}
 
-	type acase struct {
+	cases := []struct {
 		version string
 		keys    []string
+	}{
+		{version: "v1.24", keys: keysBase},
 	}
-
-	var cases []acase
-
-	if testEnv.DaemonInfo.OSType == "windows" {
-		cases = []acase{
-			{"v1.25", append(keysBase, "Mounts")},
-		}
-	} else {
-		cases = []acase{
-			{"v1.20", append(keysBase, "Mounts")},
-			{"v1.19", append(keysBase, "Volumes", "VolumesRW")},
-		}
-	}
-
 	for _, cs := range cases {
 		body := getInspectBody(c, cs.version, cleanedContainerID)
 
@@ -59,28 +47,6 @@ func (s *DockerAPISuite) TestInspectAPIContainerResponse(c *testing.T) {
 	}
 }
 
-func (s *DockerAPISuite) TestInspectAPIContainerVolumeDriverLegacy(c *testing.T) {
-	// No legacy implications for Windows
-	testRequires(c, DaemonIsLinux)
-	out := cli.DockerCmd(c, "run", "-d", "busybox", "true").Stdout()
-	cleanedContainerID := strings.TrimSpace(out)
-
-	cases := []string{"v1.19", "v1.20"}
-	for _, version := range cases {
-		body := getInspectBody(c, version, cleanedContainerID)
-
-		var inspectJSON map[string]interface{}
-		err := json.Unmarshal(body, &inspectJSON)
-		assert.NilError(c, err, "Unable to unmarshal body for version %s", version)
-
-		config, ok := inspectJSON["Config"]
-		assert.Assert(c, ok, "Unable to find 'Config'")
-		cfg := config.(map[string]interface{})
-		_, ok = cfg["VolumeDriver"]
-		assert.Assert(c, ok, "API version %s expected to include VolumeDriver in 'Config'", version)
-	}
-}
-
 func (s *DockerAPISuite) TestInspectAPIContainerVolumeDriver(c *testing.T) {
 	out := cli.DockerCmd(c, "run", "-d", "--volume-driver", "local", "busybox", "true").Stdout()
 	cleanedContainerID := strings.TrimSpace(out)
@@ -118,47 +84,6 @@ func (s *DockerAPISuite) TestInspectAPIImageResponse(c *testing.T) {
 	assert.Check(c, is.Contains(imageJSON.RepoTags, "busybox:mytag"))
 }
 
-// #17131, #17139, #17173
-func (s *DockerAPISuite) TestInspectAPIEmptyFieldsInConfigPre121(c *testing.T) {
-	// Not relevant on Windows
-	testRequires(c, DaemonIsLinux)
-	out := cli.DockerCmd(c, "run", "-d", "busybox", "true").Stdout()
-	cleanedContainerID := strings.TrimSpace(out)
-
-	cases := []string{"v1.19", "v1.20"}
-	for _, version := range cases {
-		body := getInspectBody(c, version, cleanedContainerID)
-
-		var inspectJSON map[string]interface{}
-		err := json.Unmarshal(body, &inspectJSON)
-		assert.NilError(c, err, "Unable to unmarshal body for version %s", version)
-		config, ok := inspectJSON["Config"]
-		assert.Assert(c, ok, "Unable to find 'Config'")
-		cfg := config.(map[string]interface{})
-		for _, f := range []string{"MacAddress", "NetworkDisabled", "ExposedPorts"} {
-			_, ok := cfg[f]
-			assert.Check(c, ok, "API version %s expected to include %s in 'Config'", version, f)
-		}
-	}
-}
-
-func (s *DockerAPISuite) TestInspectAPIBridgeNetworkSettings120(c *testing.T) {
-	// Not relevant on Windows, and besides it doesn't have any bridge network settings
-	testRequires(c, DaemonIsLinux)
-	out := cli.DockerCmd(c, "run", "-d", "busybox", "top").Stdout()
-	containerID := strings.TrimSpace(out)
-	cli.WaitRun(c, containerID)
-
-	body := getInspectBody(c, "v1.20", containerID)
-
-	var inspectJSON v1p20.ContainerJSON
-	err := json.Unmarshal(body, &inspectJSON)
-	assert.NilError(c, err)
-
-	settings := inspectJSON.NetworkSettings
-	assert.Assert(c, len(settings.IPAddress) != 0)
-}
-
 // Inspect for API v1.21 and up; see
 //
 // - https://github.com/moby/moby/issues/17131
diff --git a/integration-cli/docker_api_stats_test.go b/integration-cli/docker_api_stats_test.go
index 4d31aee079926..6b50bcf8f0c6a 100644
--- a/integration-cli/docker_api_stats_test.go
+++ b/integration-cli/docker_api_stats_test.go
@@ -8,13 +8,11 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
-	"sync"
 	"testing"
 	"time"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/system"
-	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/docker/client"
 	"github.com/docker/docker/integration-cli/cli"
 	"github.com/docker/docker/testutil"
@@ -166,27 +164,13 @@ func (s *DockerAPISuite) TestAPIStatsNetworkStats(c *testing.T) {
 }
 
 func (s *DockerAPISuite) TestAPIStatsNetworkStatsVersioning(c *testing.T) {
-	// Windows doesn't support API versions less than 1.25, so no point testing 1.17 .. 1.21
 	testRequires(c, testEnv.IsLocalDaemon, DaemonIsLinux)
 
 	id := runSleepingContainer(c)
 	cli.WaitRun(c, id)
-	wg := sync.WaitGroup{}
-
-	for i := 17; i <= 21; i++ {
-		wg.Add(1)
-		go func(i int) {
-			defer wg.Done()
-			apiVersion := fmt.Sprintf("v1.%d", i)
-			statsJSONBlob := getVersionedStats(c, id, apiVersion)
-			if versions.LessThan(apiVersion, "v1.21") {
-				assert.Assert(c, jsonBlobHasLTv121NetworkStats(statsJSONBlob), "Stats JSON blob from API %s %#v does not look like a <v1.21 API stats structure", apiVersion, statsJSONBlob)
-			} else {
-				assert.Assert(c, jsonBlobHasGTE121NetworkStats(statsJSONBlob), "Stats JSON blob from API %s %#v does not look like a >=v1.21 API stats structure", apiVersion, statsJSONBlob)
-			}
-		}(i)
-	}
-	wg.Wait()
+
+	statsJSONBlob := getStats(c, id)
+	assert.Assert(c, jsonBlobHasGTE121NetworkStats(statsJSONBlob), "Stats JSON blob from API does not look like a >=v1.21 API stats structure", statsJSONBlob)
 }
 
 func getNetworkStats(c *testing.T, id string) map[string]types.NetworkStats {
@@ -202,14 +186,15 @@ func getNetworkStats(c *testing.T, id string) map[string]types.NetworkStats {
 	return st.Networks
 }
 
-// getVersionedStats returns stats result for the
+// getStats returns stats result for the
 // container with id using an API call with version apiVersion. Since the
 // stats result type differs between API versions, we simply return
 // map[string]interface{}.
-func getVersionedStats(c *testing.T, id string, apiVersion string) map[string]interface{} {
+func getStats(c *testing.T, id string) map[string]interface{} {
+	c.Helper()
 	stats := make(map[string]interface{})
 
-	_, body, err := request.Get(testutil.GetContext(c), "/"+apiVersion+"/containers/"+id+"/stats?stream=false")
+	_, body, err := request.Get(testutil.GetContext(c), "/containers/"+id+"/stats?stream=false")
 	assert.NilError(c, err)
 	defer body.Close()
 
@@ -219,23 +204,6 @@ func getVersionedStats(c *testing.T, id string, apiVersion string) map[string]in
 	return stats
 }
 
-func jsonBlobHasLTv121NetworkStats(blob map[string]interface{}) bool {
-	networkStatsIntfc, ok := blob["network"]
-	if !ok {
-		return false
-	}
-	networkStats, ok := networkStatsIntfc.(map[string]interface{})
-	if !ok {
-		return false
-	}
-	for _, expectedKey := range expectedNetworkInterfaceStats {
-		if _, ok := networkStats[expectedKey]; !ok {
-			return false
-		}
-	}
-	return true
-}
-
 func jsonBlobHasGTE121NetworkStats(blob map[string]interface{}) bool {
 	networksStatsIntfc, ok := blob["networks"]
 	if !ok {
diff --git a/integration-cli/docker_api_test.go b/integration-cli/docker_api_test.go
index 085afcbeddd0d..ca1235a9ffb51 100644
--- a/integration-cli/docker_api_test.go
+++ b/integration-cli/docker_api_test.go
@@ -3,7 +3,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"io"
 	"net/http"
 	"runtime"
 	"strconv"
@@ -62,9 +61,9 @@ func (s *DockerAPISuite) TestAPIClientVersionOldNotSupported(c *testing.T) {
 	defer body.Close()
 	assert.Equal(c, resp.StatusCode, http.StatusBadRequest)
 	expected := fmt.Sprintf("client version %s is too old. Minimum supported API version is %s, please upgrade your client to a newer version", version, testEnv.DaemonVersion.MinAPIVersion)
-	content, err := io.ReadAll(body)
+	b, err := request.ReadBody(body)
 	assert.NilError(c, err)
-	assert.Equal(c, strings.TrimSpace(string(content)), expected)
+	assert.Equal(c, getErrorMessage(c, b), expected)
 }
 
 func (s *DockerAPISuite) TestAPIErrorJSON(c *testing.T) {
@@ -77,19 +76,6 @@ func (s *DockerAPISuite) TestAPIErrorJSON(c *testing.T) {
 	assert.Equal(c, getErrorMessage(c, b), runconfig.ErrEmptyConfig.Error())
 }
 
-func (s *DockerAPISuite) TestAPIErrorPlainText(c *testing.T) {
-	// Windows requires API 1.25 or later. This test is validating a behaviour which was present
-	// in v1.23, but changed in 1.24, hence not applicable on Windows. See apiVersionSupportsJSONErrors
-	testRequires(c, DaemonIsLinux)
-	httpResp, body, err := request.Post(testutil.GetContext(c), "/v1.23/containers/create", request.JSONBody(struct{}{}))
-	assert.NilError(c, err)
-	assert.Equal(c, httpResp.StatusCode, http.StatusBadRequest)
-	assert.Assert(c, strings.Contains(httpResp.Header.Get("Content-Type"), "text/plain"))
-	b, err := request.ReadBody(body)
-	assert.NilError(c, err)
-	assert.Equal(c, strings.TrimSpace(string(b)), runconfig.ErrEmptyConfig.Error())
-}
-
 func (s *DockerAPISuite) TestAPIErrorNotFoundJSON(c *testing.T) {
 	// 404 is a different code path to normal errors, so test separately
 	httpResp, body, err := request.Get(testutil.GetContext(c), "/notfound", request.JSON)
@@ -100,13 +86,3 @@ func (s *DockerAPISuite) TestAPIErrorNotFoundJSON(c *testing.T) {
 	assert.NilError(c, err)
 	assert.Equal(c, getErrorMessage(c, b), "page not found")
 }
-
-func (s *DockerAPISuite) TestAPIErrorNotFoundPlainText(c *testing.T) {
-	httpResp, body, err := request.Get(testutil.GetContext(c), "/v1.23/notfound", request.JSON)
-	assert.NilError(c, err)
-	assert.Equal(c, httpResp.StatusCode, http.StatusNotFound)
-	assert.Assert(c, strings.Contains(httpResp.Header.Get("Content-Type"), "text/plain"))
-	b, err := request.ReadBody(body)
-	assert.NilError(c, err)
-	assert.Equal(c, strings.TrimSpace(string(b)), "page not found")
-}
diff --git a/integration-cli/docker_cli_network_unix_test.go b/integration-cli/docker_cli_network_unix_test.go
index e4d3d3fe0a60a..24a241ec3a48b 100644
--- a/integration-cli/docker_cli_network_unix_test.go
+++ b/integration-cli/docker_cli_network_unix_test.go
@@ -15,7 +15,6 @@ import (
 	"time"
 
 	"github.com/docker/docker/api/types"
-	"github.com/docker/docker/api/types/versions/v1p20"
 	"github.com/docker/docker/integration-cli/cli"
 	"github.com/docker/docker/integration-cli/daemon"
 	"github.com/docker/docker/libnetwork/driverapi"
@@ -1015,22 +1014,14 @@ func (s *DockerCLINetworkSuite) TestInspectAPIMultipleNetworks(c *testing.T) {
 	cli.DockerCmd(c, "network", "connect", "mybridge1", id)
 	cli.DockerCmd(c, "network", "connect", "mybridge2", id)
 
-	body := getInspectBody(c, "v1.20", id)
-	var inspect120 v1p20.ContainerJSON
-	err := json.Unmarshal(body, &inspect120)
-	assert.NilError(c, err)
-
-	versionedIP := inspect120.NetworkSettings.IPAddress
-
 	// Current API version (API v1.21 and up)
-	body = getInspectBody(c, "", id)
+	body := getInspectBody(c, "", id)
 	var inspectCurrent types.ContainerJSON
-	err = json.Unmarshal(body, &inspectCurrent)
+	err := json.Unmarshal(body, &inspectCurrent)
 	assert.NilError(c, err)
 	assert.Equal(c, len(inspectCurrent.NetworkSettings.Networks), 3)
 
 	bridge := inspectCurrent.NetworkSettings.Networks["bridge"]
-	assert.Equal(c, bridge.IPAddress, versionedIP)
 	assert.Equal(c, bridge.IPAddress, inspectCurrent.NetworkSettings.IPAddress)
 }
 
diff --git a/integration-cli/docker_deprecated_api_v124_test.go b/integration-cli/docker_deprecated_api_v124_test.go
deleted file mode 100644
index 68ff53f42e2c5..0000000000000
--- a/integration-cli/docker_deprecated_api_v124_test.go
+++ /dev/null
@@ -1,239 +0,0 @@
-// This file will be removed when we completely drop support for
-// passing HostConfig to container start API.
-
-package main
-
-import (
-	"net/http"
-	"strings"
-	"testing"
-
-	"github.com/docker/docker/integration-cli/cli"
-	"github.com/docker/docker/testutil"
-	"github.com/docker/docker/testutil/request"
-	"gotest.tools/v3/assert"
-	is "gotest.tools/v3/assert/cmp"
-)
-
-func formatV123StartAPIURL(url string) string {
-	return "/v1.23" + url
-}
-
-func (s *DockerAPISuite) TestDeprecatedContainerAPIStartHostConfig(c *testing.T) {
-	name := "test-deprecated-api-124"
-	cli.DockerCmd(c, "create", "--name", name, "busybox")
-	config := map[string]interface{}{
-		"Binds": []string{"/aa:/bb"},
-	}
-	res, body, err := request.Post(testutil.GetContext(c), "/containers/"+name+"/start", request.JSONBody(config))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusBadRequest)
-	buf, err := request.ReadBody(body)
-	assert.NilError(c, err)
-
-	assert.Equal(c, res.StatusCode, http.StatusBadRequest)
-	assert.Assert(c, strings.Contains(string(buf), "was deprecated since API v1.22"))
-}
-
-func (s *DockerAPISuite) TestDeprecatedContainerAPIStartVolumeBinds(c *testing.T) {
-	// TODO Windows CI: Investigate further why this fails on Windows to Windows CI.
-	testRequires(c, DaemonIsLinux)
-	path := "/foo"
-	if testEnv.DaemonInfo.OSType == "windows" {
-		path = `c:\foo`
-	}
-	name := "testing"
-	config := map[string]interface{}{
-		"Image":   "busybox",
-		"Volumes": map[string]struct{}{path: {}},
-	}
-
-	res, _, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/create?name="+name), request.JSONBody(config))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusCreated)
-
-	bindPath := RandomTmpDirPath("test", testEnv.DaemonInfo.OSType)
-	config = map[string]interface{}{
-		"Binds": []string{bindPath + ":" + path},
-	}
-	res, _, err = request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+name+"/start"), request.JSONBody(config))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-
-	pth, err := inspectMountSourceField(name, path)
-	assert.NilError(c, err)
-	assert.Equal(c, pth, bindPath, "expected volume host path to be %s, got %s", bindPath, pth)
-}
-
-// Test for GH#10618
-func (s *DockerAPISuite) TestDeprecatedContainerAPIStartDupVolumeBinds(c *testing.T) {
-	// TODO Windows to Windows CI - Port this
-	testRequires(c, DaemonIsLinux)
-	name := "testdups"
-	config := map[string]interface{}{
-		"Image":   "busybox",
-		"Volumes": map[string]struct{}{"/tmp": {}},
-	}
-
-	res, _, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/create?name="+name), request.JSONBody(config))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusCreated)
-
-	bindPath1 := RandomTmpDirPath("test1", testEnv.DaemonInfo.OSType)
-	bindPath2 := RandomTmpDirPath("test2", testEnv.DaemonInfo.OSType)
-
-	config = map[string]interface{}{
-		"Binds": []string{bindPath1 + ":/tmp", bindPath2 + ":/tmp"},
-	}
-	res, body, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+name+"/start"), request.JSONBody(config))
-	assert.NilError(c, err)
-
-	buf, err := request.ReadBody(body)
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusBadRequest)
-	assert.Assert(c, strings.Contains(string(buf), "Duplicate mount point"), "Expected failure due to duplicate bind mounts to same path, instead got: %q with error: %v", string(buf), err)
-}
-
-func (s *DockerAPISuite) TestDeprecatedContainerAPIStartVolumesFrom(c *testing.T) {
-	// TODO Windows to Windows CI - Port this
-	testRequires(c, DaemonIsLinux)
-	volName := "voltst"
-	volPath := "/tmp"
-
-	cli.DockerCmd(c, "run", "--name", volName, "-v", volPath, "busybox")
-
-	name := "TestContainerAPIStartVolumesFrom"
-	config := map[string]interface{}{
-		"Image":   "busybox",
-		"Volumes": map[string]struct{}{volPath: {}},
-	}
-
-	res, _, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/create?name="+name), request.JSONBody(config))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusCreated)
-
-	config = map[string]interface{}{
-		"VolumesFrom": []string{volName},
-	}
-	res, _, err = request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+name+"/start"), request.JSONBody(config))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-
-	pth, err := inspectMountSourceField(name, volPath)
-	assert.NilError(c, err)
-	pth2, err := inspectMountSourceField(volName, volPath)
-	assert.NilError(c, err)
-	assert.Equal(c, pth, pth2, "expected volume host path to be %s, got %s", pth, pth2)
-}
-
-// #9981 - Allow a docker created volume (ie, one in /var/lib/docker/volumes) to be used to overwrite (via passing in Binds on api start) an existing volume
-func (s *DockerAPISuite) TestDeprecatedPostContainerBindNormalVolume(c *testing.T) {
-	// TODO Windows to Windows CI - Port this
-	testRequires(c, DaemonIsLinux)
-	cli.DockerCmd(c, "create", "-v", "/foo", "--name=one", "busybox")
-
-	fooDir, err := inspectMountSourceField("one", "/foo")
-	assert.NilError(c, err)
-
-	cli.DockerCmd(c, "create", "-v", "/foo", "--name=two", "busybox")
-
-	bindSpec := map[string][]string{"Binds": {fooDir + ":/foo"}}
-	res, _, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/two/start"), request.JSONBody(bindSpec))
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-
-	fooDir2, err := inspectMountSourceField("two", "/foo")
-	assert.NilError(c, err)
-	assert.Equal(c, fooDir2, fooDir, "expected volume path to be %s, got: %s", fooDir, fooDir2)
-}
-
-func (s *DockerAPISuite) TestDeprecatedStartWithTooLowMemoryLimit(c *testing.T) {
-	// TODO Windows: Port once memory is supported
-	testRequires(c, DaemonIsLinux)
-	containerID := cli.DockerCmd(c, "create", "busybox").Stdout()
-	containerID = strings.TrimSpace(containerID)
-
-	const config = `{
-                "CpuShares": 100,
-                "Memory":    524287
-        }`
-
-	res, body, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+containerID+"/start"), request.RawString(config), request.JSON)
-	assert.NilError(c, err)
-	b, err := request.ReadBody(body)
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusBadRequest)
-	assert.Assert(c, is.Contains(string(b), "Minimum memory limit allowed is 6MB"))
-}
-
-// #14640
-func (s *DockerAPISuite) TestDeprecatedPostContainersStartWithoutLinksInHostConfig(c *testing.T) {
-	// TODO Windows: Windows doesn't support supplying a hostconfig on start.
-	// An alternate test could be written to validate the negative testing aspect of this
-	testRequires(c, DaemonIsLinux)
-	name := "test-host-config-links"
-	cli.DockerCmd(c, append([]string{"create", "--name", name, "busybox"}, sleepCommandForDaemonPlatform()...)...)
-
-	hc := inspectFieldJSON(c, name, "HostConfig")
-	config := `{"HostConfig":` + hc + `}`
-
-	res, b, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+name+"/start"), request.RawString(config), request.JSON)
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-	b.Close()
-}
-
-// #14640
-func (s *DockerAPISuite) TestDeprecatedPostContainersStartWithLinksInHostConfig(c *testing.T) {
-	// TODO Windows: Windows doesn't support supplying a hostconfig on start.
-	// An alternate test could be written to validate the negative testing aspect of this
-	testRequires(c, DaemonIsLinux)
-	name := "test-host-config-links"
-	cli.DockerCmd(c, "run", "--name", "foo", "-d", "busybox", "top")
-	cli.DockerCmd(c, "create", "--name", name, "--link", "foo:bar", "busybox", "top")
-
-	hc := inspectFieldJSON(c, name, "HostConfig")
-	config := `{"HostConfig":` + hc + `}`
-
-	res, b, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+name+"/start"), request.RawString(config), request.JSON)
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-	b.Close()
-}
-
-// #14640
-func (s *DockerAPISuite) TestDeprecatedPostContainersStartWithLinksInHostConfigIdLinked(c *testing.T) {
-	// Windows does not support links
-	testRequires(c, DaemonIsLinux)
-	const name = "test-host-config-links"
-	containerID := cli.DockerCmd(c, "run", "--name", "link0", "-d", "busybox", "top").Combined()
-	containerID = strings.TrimSpace(containerID)
-	defer cli.DockerCmd(c, "stop", "link0")
-	cli.DockerCmd(c, "create", "--name", name, "--link", containerID, "busybox", "top")
-	defer cli.DockerCmd(c, "stop", name)
-
-	hc := inspectFieldJSON(c, name, "HostConfig")
-	config := `{"HostConfig":` + hc + `}`
-
-	res, b, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+name+"/start"), request.RawString(config), request.JSON)
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-	b.Close()
-}
-
-func (s *DockerAPISuite) TestDeprecatedStartWithNilDNS(c *testing.T) {
-	// TODO Windows: Add once DNS is supported
-	testRequires(c, DaemonIsLinux)
-	containerID := cli.DockerCmd(c, "create", "busybox").Stdout()
-	containerID = strings.TrimSpace(containerID)
-
-	const config = `{"HostConfig": {"Dns": null}}`
-
-	res, b, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+containerID+"/start"), request.RawString(config), request.JSON)
-	assert.NilError(c, err)
-	assert.Equal(c, res.StatusCode, http.StatusNoContent)
-	b.Close()
-
-	dns := inspectFieldJSON(c, containerID, "HostConfig.Dns")
-	assert.Equal(c, dns, "[]")
-}
diff --git a/integration-cli/docker_deprecated_api_v124_unix_test.go b/integration-cli/docker_deprecated_api_v124_unix_test.go
deleted file mode 100644
index 574f14f22bda7..0000000000000
--- a/integration-cli/docker_deprecated_api_v124_unix_test.go
+++ /dev/null
@@ -1,33 +0,0 @@
-//go:build !windows
-
-package main
-
-import (
-	"strings"
-	"testing"
-
-	"github.com/docker/docker/integration-cli/cli"
-	"github.com/docker/docker/testutil"
-	"github.com/docker/docker/testutil/request"
-	"gotest.tools/v3/assert"
-)
-
-// #19100 This is a deprecated feature test, it should be removed in Docker 1.12
-func (s *DockerNetworkSuite) TestDeprecatedDockerNetworkStartAPIWithHostconfig(c *testing.T) {
-	const netName = "test"
-	const conName = "foo"
-	cli.DockerCmd(c, "network", "create", netName)
-	cli.DockerCmd(c, "create", "--name", conName, "busybox", "top")
-
-	config := map[string]interface{}{
-		"HostConfig": map[string]interface{}{
-			"NetworkMode": netName,
-		},
-	}
-	_, _, err := request.Post(testutil.GetContext(c), formatV123StartAPIURL("/containers/"+conName+"/start"), request.JSONBody(config))
-	assert.NilError(c, err)
-	cli.WaitRun(c, conName)
-	networks := inspectField(c, conName, "NetworkSettings.Networks")
-	assert.Assert(c, strings.Contains(networks, netName), "Should contain '%s' network", netName)
-	assert.Assert(c, !strings.Contains(networks, "bridge"), "Should not contain 'bridge' network")
-}
diff --git a/integration/container/container_test.go b/integration/container/container_test.go
index aa62cb89e7276..31876aaed1b89 100644
--- a/integration/container/container_test.go
+++ b/integration/container/container_test.go
@@ -2,7 +2,6 @@ package container // import "github.com/docker/docker/integration/container"
 
 import (
 	"net/http"
-	"runtime"
 	"testing"
 
 	"github.com/docker/docker/testutil"
@@ -25,15 +24,6 @@ func TestContainerInvalidJSON(t *testing.T) {
 		"/exec/foobar/start",
 	}
 
-	// windows doesnt support API < v1.24
-	if runtime.GOOS != "windows" {
-		endpoints = append(
-			endpoints,
-			"/v1.23/containers/foobar/copy",  // deprecated since 1.8 (API v1.20), errors out since 1.12 (API v1.24)
-			"/v1.23/containers/foobar/start", // accepts a body on API < v1.24
-		)
-	}
-
 	for _, ep := range endpoints {
 		ep := ep
 		t.Run(ep[1:], func(t *testing.T) {
diff --git a/integration/container/inspect_test.go b/integration/container/inspect_test.go
index 39f7eeab78004..3f8e10628faf0 100644
--- a/integration/container/inspect_test.go
+++ b/integration/container/inspect_test.go
@@ -1,53 +1,17 @@
 package container // import "github.com/docker/docker/integration/container"
 
 import (
-	"encoding/json"
 	"runtime"
 	"strings"
 	"testing"
-	"time"
 
 	containertypes "github.com/docker/docker/api/types/container"
-	"github.com/docker/docker/client"
 	"github.com/docker/docker/integration/internal/container"
 	"github.com/docker/docker/testutil/request"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
-	"gotest.tools/v3/poll"
-	"gotest.tools/v3/skip"
 )
 
-func TestInspectCpusetInConfigPre120(t *testing.T) {
-	skip.If(t, testEnv.DaemonInfo.OSType == "windows" || !testEnv.DaemonInfo.CPUSet)
-
-	ctx := setupTest(t)
-	apiClient := request.NewAPIClient(t, client.WithVersion("1.19"))
-
-	name := strings.ToLower(t.Name())
-	// Create container with up to-date-API
-	container.Run(ctx, t, request.NewAPIClient(t), container.WithName(name),
-		container.WithCmd("true"),
-		func(c *container.TestContainerConfig) {
-			c.HostConfig.Resources.CpusetCpus = "0"
-		},
-	)
-	poll.WaitOn(t, container.IsInState(ctx, apiClient, name, "exited"), poll.WithDelay(100*time.Millisecond))
-
-	_, body, err := apiClient.ContainerInspectWithRaw(ctx, name, false)
-	assert.NilError(t, err)
-
-	var inspectJSON map[string]interface{}
-	err = json.Unmarshal(body, &inspectJSON)
-	assert.NilError(t, err, "unable to unmarshal body for version 1.19: %s", err)
-
-	config, ok := inspectJSON["Config"]
-	assert.Check(t, is.Equal(true, ok), "Unable to find 'Config'")
-
-	cfg := config.(map[string]interface{})
-	_, ok = cfg["Cpuset"]
-	assert.Check(t, is.Equal(true, ok), "API version 1.19 expected to include Cpuset in 'Config'")
-}
-
 func TestInspectAnnotations(t *testing.T) {
 	ctx := setupTest(t)
 	apiClient := request.NewAPIClient(t)
diff --git a/integration/container/kill_test.go b/integration/container/kill_test.go
index 8992dd23dca50..4d44f02a6ba1d 100644
--- a/integration/container/kill_test.go
+++ b/integration/container/kill_test.go
@@ -6,7 +6,6 @@ import (
 	"time"
 
 	containertypes "github.com/docker/docker/api/types/container"
-	"github.com/docker/docker/client"
 	"github.com/docker/docker/integration/internal/container"
 	"github.com/docker/docker/testutil"
 	"github.com/docker/docker/testutil/request"
@@ -133,15 +132,6 @@ func TestKillStoppedContainer(t *testing.T) {
 	assert.Assert(t, is.Contains(err.Error(), "is not running"))
 }
 
-func TestKillStoppedContainerAPIPre120(t *testing.T) {
-	skip.If(t, testEnv.DaemonInfo.OSType == "windows", "Windows only supports 1.25 or later")
-	ctx := setupTest(t)
-	apiClient := request.NewAPIClient(t, client.WithVersion("1.19"))
-	id := container.Create(ctx, t, apiClient)
-	err := apiClient.ContainerKill(ctx, id, "SIGKILL")
-	assert.NilError(t, err)
-}
-
 func TestKillDifferentUserContainer(t *testing.T) {
 	// TODO Windows: Windows does not yet support -u (Feb 2016).
 	skip.If(t, testEnv.DaemonInfo.OSType == "windows", "User containers (container.Config.User) are not yet supported on %q platform", testEnv.DaemonInfo.OSType)
diff --git a/integration/system/info_linux_test.go b/integration/system/info_linux_test.go
index 98b3367990a78..a6d836091473e 100644
--- a/integration/system/info_linux_test.go
+++ b/integration/system/info_linux_test.go
@@ -31,7 +31,6 @@ func TestInfoBinaryCommits(t *testing.T) {
 
 func TestInfoAPIVersioned(t *testing.T) {
 	ctx := testutil.StartSpan(baseContext, t)
-	// Windows only supports 1.25 or later
 
 	res, body, err := req.Get(ctx, "/v1.24/info")
 	assert.NilError(t, err)
diff --git a/runconfig/config.go b/runconfig/config.go
index 3ba1609e9101f..81047ea6d1887 100644
--- a/runconfig/config.go
+++ b/runconfig/config.go
@@ -27,11 +27,6 @@ func (r ContainerDecoder) DecodeConfig(src io.Reader) (*container.Config, *conta
 	return decodeContainerConfig(src, si)
 }
 
-// DecodeHostConfig makes ContainerDecoder to implement httputils.ContainerDecoder
-func (r ContainerDecoder) DecodeHostConfig(src io.Reader) (*container.HostConfig, error) {
-	return decodeHostConfig(src)
-}
-
 // decodeContainerConfig decodes a json encoded config into a ContainerConfigWrapper
 // struct and returns both a Config and a HostConfig struct, and performs some
 // validation. Certain parameters need daemon-side validation that cannot be done
diff --git a/runconfig/config_test.go b/runconfig/config_test.go
index c001fe932ec45..ff4a412e1693c 100644
--- a/runconfig/config_test.go
+++ b/runconfig/config_test.go
@@ -26,11 +26,10 @@ func TestDecodeContainerConfig(t *testing.T) {
 		imgName  string
 	)
 
+	// FIXME (thaJeztah): update fixtures for more current versions.
 	if runtime.GOOS != "windows" {
 		imgName = "ubuntu"
 		fixtures = []f{
-			{"fixtures/unix/container_config_1_14.json", strslice.StrSlice{}},
-			{"fixtures/unix/container_config_1_17.json", strslice.StrSlice{"bash"}},
 			{"fixtures/unix/container_config_1_19.json", strslice.StrSlice{"bash"}},
 		}
 	} else {
diff --git a/runconfig/fixtures/unix/container_config_1_14.json b/runconfig/fixtures/unix/container_config_1_14.json
deleted file mode 100644
index b08334c0950e4..0000000000000
--- a/runconfig/fixtures/unix/container_config_1_14.json
+++ /dev/null
@@ -1,30 +0,0 @@
-{
-     "Hostname":"",
-     "Domainname": "",
-     "User":"",
-     "Memory": 1000,
-     "MemorySwap":0,
-     "CpuShares": 512,
-     "Cpuset": "0,1",
-     "AttachStdin":false,
-     "AttachStdout":true,
-     "AttachStderr":true,
-     "PortSpecs":null,
-     "Tty":false,
-     "OpenStdin":false,
-     "StdinOnce":false,
-     "Env":null,
-     "Cmd":[
-             "bash"
-     ],
-     "Image":"ubuntu",
-     "Volumes":{
-             "/tmp": {}
-     },
-     "WorkingDir":"",
-     "NetworkDisabled": false,
-     "ExposedPorts":{
-             "22/tcp": {}
-     },
-     "RestartPolicy": { "Name": "always" }
-}
diff --git a/runconfig/fixtures/unix/container_config_1_17.json b/runconfig/fixtures/unix/container_config_1_17.json
deleted file mode 100644
index 0d780877b4bcf..0000000000000
--- a/runconfig/fixtures/unix/container_config_1_17.json
+++ /dev/null
@@ -1,50 +0,0 @@
-{
-     "Hostname": "",
-     "Domainname": "",
-     "User": "",
-     "Memory": 1000,
-     "MemorySwap": 0,
-     "CpuShares": 512,
-     "Cpuset": "0,1",
-     "AttachStdin": false,
-     "AttachStdout": true,
-     "AttachStderr": true,
-     "Tty": false,
-     "OpenStdin": false,
-     "StdinOnce": false,
-     "Env": null,
-     "Cmd": [
-             "date"
-     ],
-     "Entrypoint": "bash",
-     "Image": "ubuntu",
-     "Volumes": {
-             "/tmp": {}
-     },
-     "WorkingDir": "",
-     "NetworkDisabled": false,
-     "MacAddress": "12:34:56:78:9a:bc",
-     "ExposedPorts": {
-             "22/tcp": {}
-     },
-     "SecurityOpt": [""],
-     "HostConfig": {
-       "Binds": ["/tmp:/tmp"],
-       "Links": ["redis3:redis"],
-       "LxcConf": {"lxc.utsname":"docker"},
-       "PortBindings": { "22/tcp": [{ "HostPort": "11022" }] },
-       "PublishAllPorts": false,
-       "Privileged": false,
-       "ReadonlyRootfs": false,
-       "Dns": ["8.8.8.8"],
-       "DnsSearch": [""],
-       "DnsOptions": [""],
-       "ExtraHosts": null,
-       "VolumesFrom": ["parent", "other:ro"],
-       "CapAdd": ["NET_ADMIN"],
-       "CapDrop": ["MKNOD"],
-       "RestartPolicy": { "Name": "", "MaximumRetryCount": 0 },
-       "NetworkMode": "bridge",
-       "Devices": []
-    }
-}
diff --git a/runconfig/fixtures/unix/container_hostconfig_1_14.json b/runconfig/fixtures/unix/container_hostconfig_1_14.json
deleted file mode 100644
index c72ac91cabe26..0000000000000
--- a/runconfig/fixtures/unix/container_hostconfig_1_14.json
+++ /dev/null
@@ -1,18 +0,0 @@
-{
-    "Binds": ["/tmp:/tmp"],
-    "ContainerIDFile": "",
-    "LxcConf": [],
-    "Privileged": false,
-    "PortBindings": {
-        "80/tcp": [
-            {
-                "HostIp": "0.0.0.0",
-                "HostPort": "49153"
-            }
-        ]
-    },
-    "Links": ["/name:alias"],
-    "PublishAllPorts": false,
-    "CapAdd": ["NET_ADMIN"],
-    "CapDrop": ["MKNOD"]
-}
diff --git a/runconfig/fixtures/unix/container_hostconfig_1_19.json b/runconfig/fixtures/unix/container_hostconfig_1_19.json
deleted file mode 100644
index 5ca8aa7e19483..0000000000000
--- a/runconfig/fixtures/unix/container_hostconfig_1_19.json
+++ /dev/null
@@ -1,30 +0,0 @@
-{
-    "Binds": ["/tmp:/tmp"],
-    "Links": ["redis3:redis"],
-    "LxcConf": {"lxc.utsname":"docker"},
-    "Memory": 0,
-    "MemorySwap": 0,
-    "CpuShares": 512,
-    "CpuPeriod": 100000,
-    "CpusetCpus": "0,1",
-    "CpusetMems": "0,1",
-    "BlkioWeight": 300,
-    "OomKillDisable": false,
-    "PortBindings": { "22/tcp": [{ "HostPort": "11022" }] },
-    "PublishAllPorts": false,
-    "Privileged": false,
-    "ReadonlyRootfs": false,
-    "Dns": ["8.8.8.8"],
-    "DnsSearch": [""],
-    "ExtraHosts": null,
-    "VolumesFrom": ["parent", "other:ro"],
-    "CapAdd": ["NET_ADMIN"],
-    "CapDrop": ["MKNOD"],
-    "RestartPolicy": { "Name": "", "MaximumRetryCount": 0 },
-    "NetworkMode": "bridge",
-    "Devices": [],
-    "Ulimits": [{}],
-    "LogConfig": { "Type": "json-file", "Config": {} },
-    "SecurityOpt": [""],
-    "CgroupParent": ""
-}
diff --git a/runconfig/hostconfig.go b/runconfig/hostconfig.go
index 8a9e65f1a2bc5..84a4ae0b6fb16 100644
--- a/runconfig/hostconfig.go
+++ b/runconfig/hostconfig.go
@@ -1,23 +1,12 @@
 package runconfig // import "github.com/docker/docker/runconfig"
 
 import (
-	"io"
 	"strings"
 
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/network"
 )
 
-// DecodeHostConfig creates a HostConfig based on the specified Reader.
-// It assumes the content of the reader will be JSON, and decodes it.
-func decodeHostConfig(src io.Reader) (*container.HostConfig, error) {
-	var w ContainerConfigWrapper
-	if err := loadJSON(src, &w); err != nil {
-		return nil, err
-	}
-	return w.getHostConfig(), nil
-}
-
 // SetDefaultNetModeIfBlank changes the NetworkMode in a HostConfig structure
 // to default if it is not populated. This ensures backwards compatibility after
 // the validation of the network mode was moved from the docker CLI to the
diff --git a/runconfig/hostconfig_test.go b/runconfig/hostconfig_test.go
index 77f1de0ecbd91..a3ac0f9cf0734 100644
--- a/runconfig/hostconfig_test.go
+++ b/runconfig/hostconfig_test.go
@@ -3,51 +3,12 @@
 package runconfig // import "github.com/docker/docker/runconfig"
 
 import (
-	"bytes"
-	"fmt"
-	"os"
 	"testing"
 
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/pkg/sysinfo"
-	"gotest.tools/v3/assert"
 )
 
-func TestDecodeHostConfig(t *testing.T) {
-	fixtures := []struct {
-		file string
-	}{
-		{"fixtures/unix/container_hostconfig_1_14.json"},
-		{"fixtures/unix/container_hostconfig_1_19.json"},
-	}
-
-	for _, f := range fixtures {
-		b, err := os.ReadFile(f.file)
-		if err != nil {
-			t.Fatal(err)
-		}
-
-		c, err := decodeHostConfig(bytes.NewReader(b))
-		if err != nil {
-			t.Fatal(fmt.Errorf("Error parsing %s: %v", f, err))
-		}
-
-		assert.Check(t, !c.Privileged)
-
-		if l := len(c.Binds); l != 1 {
-			t.Fatalf("Expected 1 bind, found %d\n", l)
-		}
-
-		if len(c.CapAdd) != 1 && c.CapAdd[0] != "NET_ADMIN" {
-			t.Fatalf("Expected CapAdd NET_ADMIN, got %v", c.CapAdd)
-		}
-
-		if len(c.CapDrop) != 1 && c.CapDrop[0] != "NET_ADMIN" {
-			t.Fatalf("Expected CapDrop NET_ADMIN, got %v", c.CapDrop)
-		}
-	}
-}
-
 func TestValidateResources(t *testing.T) {
 	type resourceTest struct {
 		ConfigCPURealtimePeriod  int64