employer's competition with companies elsewhere. United States v. Darby, 312 U. S. 100, followed. Pp. 188-191.

(b) Another rational basis is the promotion of labor peace by the regulation of wages and hours, subjects of frequent labor disputes. Pp. 191-192.

(c) The class of employers subject to the Act, approved in Darby, supra, was not enlarged by the addition of the "enterprise concept." P. 193.

2. The commerce power provides a constitutional basis for extension of the Act to state-operated schools and hospitals. Pp. 193-199.

(a) Congress has "interfered with" state functions only to the extent that it subjects a State to the same minimum wage and overtime pay limitations as other employers whose activities affect commerce. Pp. 193-194.

(b) Labor conditions in schools and hospitals can affect commerce and are within the reach of the commerce power. Pp. 194-195.

(c) Where a State is engaging in economic activities that are validly regulated by the Federal Government when engaged in by private persons, the State may be forced to conform its activities to federal regulation. United States v. California, 297 U. S. 175. Pp. 195–199.

3. Questions concerning the States' sovereign immunity from suit and whether particular state-operated institutions have employees handling goods in commerce are reserved for appropriate concrete cases. Pp. 199-201.

269 F. Supp. 826, affirmed.

Alan M. Wilner, Assistant Attorney General of Maryland, and Charles Alan Wright argued the cause for appellants. With Mr. Wilner on the brief for appellant the State of Maryland et al. were the Attorneys General for their respective States as follows: Francis B. Burch of Maryland, Crawford C. Martin of Texas, MacDonald Gallion of Alabama, Darrell F. Smith of Arizona, Joe Purcell of Arkansas, Duke W. Dunbar of Colorado, David Buckson of Delaware, Earl Faircloth of Florida, Bert T. Kobayashi of Hawaii, William G. Clark of Illinois, Richard C. Turner of Iowa, Robert C. Londerholm

of Kansas, James S. Erwin of Maine, Elliot L. Richardson of Massachusetts, Joe T. Patterson of Mississippi, Norman H. Anderson of Missouri, Clarence A. H. Meyer of Nebraska, Arthur J. Sills of New Jersey, Boston E. Witt of New Mexico, T. Wade Bruton of North Carolina, Helgi Johanneson of North Dakota, William B. Saxbe of Ohio, G. T. Blankenship of Oklahoma, Daniel R. McLeod of South Carolina, Frank L. Farrar of South Dakota, James L. Oakes of Vermont, Robert Y. Button of Virginia, and James E. Barrett of Wyoming; and A. J. Carubbi, Jr., Executive Assistant Attorney General of Texas, Hawthorne Phillips, Assistant Attorney General of Texas, and James V. Noble, Assistant Attorney General of New Mexico. With Mr. Wright on the brief for appellant the State of Texas were Messrs. Martin, Carubbi, and Phillips, and Nola White, First Assistant Attorney General. Cecil A. Morgan filed a brief for appellant Fort Worth Independent School District.

Solicitor General Griswold argued the cause for appellees. With him on the brief were Assistant Attorney General Weisl, Louis F. Claiborne, John S. Martin, Jr., and Morton Hollander.

Briefs of amici curiae, urging affirmance, were filed by J. Albert Woll, Laurence Gold, and Thomas E. Harris for the Americar, Federation of Labor and Congress of Industrial Organizations, and by Henry Kaiser and Ronald Rosenberg for the American Federation of State, County, and Municipal Employees, AFL-CIO.

MR. JUSTICE HARLAN delivered the opinion of the Court.

As originally enacted,' the Fair Labor Standards Act of 1938 required every employer to pay each of his employees "engaged in commerce or in the production

152 Stat. 1060.

of goods for commerce" 2 a certain minimum hourly wage, and to pay at a higher rate for work in excess of a certain maximum number of hours per week. The Act defined the term "employer" so as to exclude "the United States or any State or political subdivision of a State . This case involves the constitutionality of two sets of amendments to the original enactment.

In 1961, Congress changed the basis of employee coverage: instead of extending protection to employees individually connected to interstate commerce, the Act now covers all employees of any "enterprise" engaged in commerce or production for commerce, provided the enterprise also falls within certain listed categories. In 1966, Congress added to the list of categories the following:

"(4) is engaged in the operation of a hospital, an institution primarily engaged in the care of the sick, the aged, the mentally ill or defective who reside on the premises of such institution, a school for the mentally or physically handicapped or gifted children, an elementary or secondary school, or an insti

§§ 6 (a), 7 (a), 52 Stat. 1062, 1063.

3§3 (d), 52 Stat. 1060.

The minimum wage requirement, 29 U. S. C. § 206 (1964 ed., Supp. II), now reads as follows: "(a) Every employer shall pay to each of his employees who in any workweek is engaged in commerce or in the production of goods for commerce, or is employed in an enterprise engaged in commerce or in the production of goods for commerce, wages at the following rates. . . ." The maximum hours requirement, 29 U. S. C. § 207 (1964 ed., Supp. II), now contains a similar definition of covered employees. The term "enterprise engaged in commerce or in the production of goods for commerce" is defined by 29 U. S. C. § 203 (s) (1964 ed., Supp. II) to mean "an enterprise which has employees engaged in commerce or in the production of goods for commerce, including employees handling, selling, or otherwise working on goods that have been moved in or produced for commerce by any person, and which-[falls in any one of four listed categories]

tution of higher education (regardless of whether or not such hospital, institution, or school is public or private or operated for profit or not for profit)." At the same time, Congress modified the definition of "employer" so as to remove the exemption of the States and their political subdivisions with respect to employees of hospitals, institutions, and schools.

The State of Maryland, since joined by 27 other States and one school district, brought this action against the Secretary of Labor to enjoin enforcement of the Act insofar as it now applies to schools and hospitals operated by the States or their subdivisions. The plaintiffs made four contentions. They argued that the expansion of coverage through the "enterprise concept" was beyond the power of Congress under the Commerce Clause. They contended that coverage of state-operated hospitals and schools was also beyond the commerce power. They asserted that the remedial provisions of the Act, if applied to the States, would conflict with the Eleventh Amendment. Finally, they urged that even if their constitutional arguments were rejected, the court should declare that schools and hospitals, as enterprises, do not have the statutorily required relationship to interstate

commerce.

A three-judge district court, convened pursuant to 28 U. S. C. § 2282, declined to issue a declaratory judgment or an injunction. Three opinions were written. Judges Winter and Thomsen, constituting the majority, concluded for different reasons that the adoption of the "enterprise concept" of coverage and the extension of coverage to state institutions could not be said, on the

580 Stat. 832, 29 U. S. C. § 203 (s) (4) (1964 ed., Supp. II). 680 Stat. 831, 29 U. S. C. § 203 (d) (1964 ed., Supp. II). 729 U. S. C. §§ 216 (b), 216 (c), 217.

$ 269 F. Supp. 826.

face of the Act, to exceed Congress' power under the Commerce Clause. Both declined to consider the Eleventh Amendment and statutory contentions. Judge Northrop dissented, concluding that the amendments exceeded the commerce power because they transgressed the sovereignty of the States.

We noted probable jurisdiction of the plaintiffs' appeal, 389 U. S. 1031. For reasons to follow, we affirm the judgment of the District Court.

I.

We turn first to the adoption in 1961 of the "enterprise concept." Whereas the Act originally extended to every employee "who is engaged in commerce or in the production of goods for commerce," it now protects every employee who "is employed in an enterprise engaged in commerce or in the production of goods for commerce." Such an enterprise is defined as one which, along with other qualifications, "has employees engaged in commerce or in the production of goods for commerce. . . ." 10 Thus the effect of the 1961 change was to extend protection to the fellow employees of any employee who would have been protected by the original Act, but not to enlarge the class of employers subject to the Act.

In United States v. Darby, 312 U. S. 100, this Court found the original Act a legitimate exercise of congressional power to regulate commerce among the States. Appellants accept the Darby decision, but contend that the extension of protection to fellow employees of those originally covered exceeds the commerce power. We conclude, to the contrary, that the constitutionality of the "enterprise concept" is settled by the reasoning of Darby itself and is independently established by principles stated in other cases.

929 U. S. C. §§ 206 (a), 207 (a) (1964 ed., Supp. II). 10 29 U. S. C. § 203 (s) (1964 ed., Supp. II).