Mr. Justice Van Devanter
delivered the opinion of the court.
While in the service of a railroad company in the State of New York, James Winfield sustained a personal injury *148whereby he lost the use of an eye. At that time the railroad company was engaging in interstate commerce as a common carrier and Winfield was employed by.it in such commerce. The injury was not due to any fault or negligence of the carrier, or of any of its officers, agents or employees, but arose out of one of the ordinary risks of the work in which Winfield was engaged. He was a section laborer assisting in the repair of the carrier’s main track and while tamping cross-ties struck a pebble which chanced to rebound and hit his eye. Following the injury he sought compensation therefor from the carrier under the Workmen’s Compensation Law of the State 1 and an award was made to him by the state commission, one member dissenting. The carrier appealed and the award was affirmed by the Appellate Division of the Supreme Court, two judges dissenting, 168 App. Div. 351, and also by the Court of Appeals, 216 N. Y. 284. Before the commission and in the state courts the carrier insisted that its liability or. obligation and the employee’s right were governed exclusively by the Employers’ Liability Act of Congress, c. 149, 35 Stat. 65; c. 143, 36 Stat. 291, and therefore that no award could be made under the law of the State. That insistence is renewed here.
It is settled that under the commerce clause of the Constitution Congress may regulate the obligation of common carriers and the rights of their employees arising out of injuries sustained by the latter where both are engaged in interstate commerce; and it also is settled' that when Congress acts upon the subject all state laws covering the same field are necessarily superseded by reason of the supremacy of- the national authority.2 Congress acted *149upon the subject in passing the Employers’ Liability Act, and the extent to which that act covers the field is the point in controversy. By one side it is said that the act, although regulating the liability or obligation of the carrier and the right of the employee where the injury results-in whole or in part from negligence attributable to the carrier, does not cover injuries occurring without such negligence, and therefore leaves that class of injuries to be dealt with by state laws; and by the other side it is said that the act covers both classes of injuries and is exclusive as to both. The state decisions upon the point aré conflicting. The New York court in the present case and the New Jersey court in Winfield v. Erie R. R. Co., 88 N. J. L. 619, hold that the act relates' only to injuries resulting from negligence, while the California court in Smith v. Industrial Accident Commission, 26 Cal. App. 560, and the Illinois court in Staley v. Illinois Central R. R. Co., 268 Illinois, 356, hold that it has a broader scope and makes negligence a test, — not of the applicability of the act, but of the carrier’s duty or obligation to respond pecuniarily for the injury.
In our opinion the latter view is right and the other wrong. Whether and in what circumstances railroad companies engaging in interstate commerce shall be required to compensate their employees in such commerce for injuries sustained therein are matters in which the Nation as a whole is interested and there are weighty considerations why the controlling law should be uniform and not change at every state line. Baltimore & Ohio R. R. Co. v. Baugh, 149 U. S. 368, 378-379. It was largely in recognition of this that the Employers’ Liability Act was enacted by Congress. Second Employers’ Liability Cases, 223 U. S. 1, 51. It was drafted and passed shortly follow*150ing a message from the President advocating an adequate national law covering all such injuries and leaving to the action of the several States only the injuries occurring in intrastate employment. • Cong* Rec., 60th Cong., 1st sess., 1347. And the reports of the congressional committees having the bill in charge disclose, without any uncertainty, that it was intended to be very comprehensive, to withdraw all injuries .to railroad employees in interstate commerce from the operation of varying state laws and to apply to them, a national law having a uniform operation throughout all the States. House Report No. 1386 and Senate Report No. 460, 60th Cong., 1st sess. Thus, in the House Report it is said: “It [the bill] is intended in its scope to cover, all commerce to which the regulative power of Congress extends ... by this bill it is hoped to fix a uniform rule of liability throughout the Union with reference to the liability of common carriers to their employees. ... A Federal statute of this character will supplant the numerous State statutes on the subject so far as they relate to interstate" commerce. It will create uniformity throughout the Union, and the legal status of such employer’s liability for personal injuries instead of being subject to numerous rules will be fixed by one rule in all the States.”
True, the act does not require the carrier to respond for injuries occurring where it is not chargeable with negligence, but this is because Congress, in its discretion, acted upon the principle that compensation should be exacted from the carrier .where, and only where, the injury results from negligence imputable to it. Every part of the act conforms to this principle, and no part points to any purpose to leave the States free to require compensation where the act withholds it. By declaring in § 1 that the carrier shall be liable in damages for an injury to the employee “resulting in whole or in part from the negligence of any of the officers, agents, or employees of such carrier, *151or by reason of any defect or insufficiency, due to its negligence, in its cars, engines, appliances, machinery, track,” etc.,1 the act plainly shows, as was expressly held in Seaboard Air Line Ry. v. Horton, 233 U. S. 492, 501, that it was the intention of Congress to make negligence the basis of the employee’s right to damages,-and to exclude responsibility of the carrier to the employee for an injury not resulting from its negligence or that of its officers, agents or other employees. The same principle is seen also in § 3, which requires that where the carrier and the employee are both negligent the recovery shall be diminished in proportion to the employee’s contribution to the total negligence, and in § 4, which regards inr juries arising.from risks assumed by the employee as among those for which the carrier should not be made to respond. The committee reports upon the bill show that this principle was adopted' deliberately, notwithstanding there were those within and without the committees who looked with greater favor upon a different principle which puts negligence out of view and regards the employee as entitled to compensation wherever the injury is an incident of the service in which he is employed. A few years after the passage of the act a legislative commission drafted and the Committees on the Judiciary in the two houses of Congress favorably reported a bill substituting the latter principle for the other, Senate Report No.. 553, 62d Cong., 2d sess., House Report No. 1441, 62d Cong., 3d sess., but that bill did not become a law.
That the act is comprehensive and also exclusive is distinctly recognized in repeated decisions of- this court. Thus, in Missouri, Kansas & Texas Ry. Co. v. Wulf, 226 U. S. 570, 576, and other cases, it is pointed out that the subject which the act covers is “the responsibility of *152interstate carriers by railroad to their employés injured in-such commerce”; in Michigan Central R. R. Co. v. Vreeland, 227 U. S. 59, 66, 67, it is said that “we may not piece out this act of Congress by resorting to the local statutes of the State of procedure or that of the injury,” that by it “Congress has undertaken to cover the subject of the liability of railroad companies to their employés injured while engaged in interstate commerce,” and that it is “paramount and exclusive”; in North Carolina R. R. Co. v. Zachary, 232 U. S. 248, 256, it is held that where it appears that the injury occurred while the carrier was engaged and the employee employed in interstate commerce the federal act governs to the exclusion of the state law; in Seaboard Air Line Ry. v. Horton, supra, pp. 501, 503, it is said not only that Congress intended “to exclude responsibility of the carrier to its employés” in the absence of negligence, but that it is not conceivable that Congress “intended to permit the legislatures of the several States to determine the effect of contributory negligence and assumption'of risk, by enacting statutes for the safety of employés, since this would in effect relegate to state control two of the essential factors that determine the responsibility of the employer;” and in Wabash R. R. Co. v. Hayes, 234 U. S. 86, 89, it is said: “Had the injury occurred in interstate commerce, as was alleged, the Federal act undoubtedly would have been controlling and a recovery could not have been had under the common or statute law of the State; in other words, the Federal act would have been exclusive in its operation, not merely cumulative [citing cases]. On the other hand, if the injury occurred outside of interstate commerce, the Federal act was without application and the law of the State was controlling.”
The act is entitled, “An Act Relating to the liability of common carriers by railroad to their employees in certain cases,” and the suggestion is made that the words “in *153certain cases” require that the act be restrictively construed! But we think these words are intended to do no more than to bring the title into reasonable accord with the body of the act, which discloses in exact terms that it is not to embrace all cases of injury to the employees of such carriers, but only such as occur while the carrier is engaging and the employee is employed in “commerce between any of the several States,” etc. See Employers’ Liability Cases, 207 U. S. 463.
Only by disturbing the uniformity which the act is designed to secure and by departing from the principle which it is intended to enforce can the several States require such carriers to compensate their employees for injuries in interstate commerce occurring without negligence. But no State is at liberty thus to interfere with the operation of a law of Congress. As before indicated, it is a mistake to suppose that injuries occurring without negligence are not reached or affected by the act, for, as is said in Prigg v. Pennsylvania, 16 Pet. 539, 617, “if Congress have a constitutional power to regulate a particular subject, and they do actually regulate it in a given manner, and in a certain form, it cannot be that the state legislatures have a right to interfere, and, as it were, by way of complement to the legislation of Congress, to prescribe additional regulations, and what they may deem auxiliary provisions for the same purpose. In such a case, the legislation of Congress, in what it does prescribe, manifestly indicates that it does not intend that there shall be any farther legislation to act upon the subject-matter. Its silence as to what it does not do, is as expressive of what its intention is as the direct provisions made by it.” Thus the act is as comprehensive of injuries occurring without negligence, as to which class it impliedly excludes liability, as it is of those as to which it imposes liability. In other words, it is a regulation , of the carriers’ duty or obligation as to both. And the reasons which operate to prevent the *154States from dispensing with compensation where the act requires it equally prevent them from requiring compensation where the act withholds or excludes it.
■ It follows that in the present case the award under the state law cannot be sustained.
Judgment reversed.
See New York Central R. R. Co. v. White, 243 U. S. 188.
Second Employers’ Liability Cases, 223 U. S. 1, 53-55; St. Louis, Iron Mountain & Southern Ry. Co. v. Hesterly, 228 U. S. 702; St. Louis, San Francisco & Texas Ry. Co. v. Seale, 229 U. S. 156; Taylor v. Taylor, 232 U. S. 363; Chicago, Rock Island & Pacific Ry. Co. v. Devine, 239 *149U. S. 52; Texas & Pacific Ry. Co. v. Rigsby, 241 U. S. 33, 41; Northern Pacific Ry. Co. v. Washington, 222 U. S. 370; Erie R. R. Co. v. New York, 233 U. S. 671; Southern Ry. Co. v. Railroad Commission, 236 U. S. 439.
The act is printed in full in Second Employers’ Liability Cases, 223 U. S. 1, 6-10.