Justices Harlan, Brown, McKenna and Day, JJ:

The combination is, within the meaning of the act of Congress of July 2, 1890, known as the Anti-Trust Act, a "trust"; but if not, it is a combination in restraint of interstate and international commerce, and that is enough to bring it under the condemnation of the act.

From prior cases in this court, the following propositions are deducible, and embrace this case:

Although the act of Congress known as the Anti-Trust Act has no reference to the mere manufacture or production of articles or commodities within the limits of the several States, it embraces and declares to be illegal every contract, combination or conspiracy, in whatever form, of whatever nature, and whoever may be parties to it, which directly or necessarily operates in restraint of trade or commerce among the several States or with foreign nations.

The act is not limited to restraints of interstate and international trade or commerce that are unreasonable in their nature, but embraces all direct restraints, reasonable or unreasonable, imposed by any combination, conspiracy or monopoly upon such trade or commerce.

Railroad carriers engaged in interstate or international trade or commerce are embraced by the act.

Combinations, even among private manufacturers or dealers, whereby interstate or international commerce is restrained are equally embraced by the act

Congress has the power to establish rules by which interstate and international commerce shall be governed, and, by the Anti-Trust Act, has prescribed the rule of free competition among those engaged in such commerce.

Every combination or conspiracy which would extinguish competition between otherwise competing railroads, engaged in interstate trade or commerce, and which would in that way restrain such trade or commerce, is made illegal by the act.

The natural effect of competition is to increase commerce, and an agreement whose direct effect is to prevent this play of competition restrains, instead of promotes, trade and commerce.

To vitiate a combination such as the act of Congress condemns, it need not be shown that such combination, in fact, results, or will result, in a total suppression of trade or in a complete monopoly, but it is only essential to show that, by its necessary operation, it tends to restrain interstate or international trade or commerce, or tends to create a monopoly in such trade or commerce, and to deprive the public of the advantages that flow from free competition.

The constitutional guarantee of liberty of contract does not prevent Congress from prescribing the rule of free competition for those engaged in interstate and international commerce.

Under its power to regulate commerce among the several States and with foreign nations, Congress had authority to enact the statute in question. United States v. E. C. Knight Co., 156 U.S. 1; United States v Trans-Missouri Freight Association, 166 U.S. 290; United States v. Joint Traffic Association, 171 U.S. 505; Hopkins v United States, 171 U.S. 578; Anderson v. United States, 171 U.S. 604; Addyston Pipe & Steel Co. v United States, 175 U.S. 211; Montague & Co. v. Lowrey, 193 U.S. 38.

Congress may protect the freedom of interstate commerce by any means that are appropriate and that are lawful and not prohibited by the Constitution.

If, in the judgment of Congress, the public convenience or the general welfare will be best subserved when the natural laws of competition are left undisturbed by those engaged in interstate commerce, that must be, for all, the end of the matter if this is to remain a government of laws, and not of men.

When Congress declared contracts, combinations and conspiracies in restraint of trade or commerce to be illegal, it did nothing more than apply to interstate commerce a rule that had been long applied by the several States when dealing with combinations that were in restraint of their domestic commerce.

Subject to such restrictions as are imposed by the Constitution upon the exercise of all power, the power of Congress over interstate and international commerce is as full and complete as is the power of any State over its domestic commerce.

No State can, by merely creating a corporation, or in any other mode, project its authority into other States so as to prevent Congress from exerting the power it possesses under the Constitution over interstate and international commerce, or so as to exempt its corporation engaged in interstate commerce from obedience to any rule lawfully established by Congress for such commerce; nor can any State give a corporation created under its laws authority to restrain interstate or international commerce against the will of the nation as lawfully expressed by Congress. Every corporation created by a State is necessarily subject to the supreme law of the land.

Whilst every instrumentality of domestic commerce is subject to state control, every instrumentality of interstate commerce may be reached and controlled by national authority, so far as to compel it to respect the rules for such commerce lawfully established by Congress.

By Mr. Justice Brewer:

The act of July 2, 1890, was leveled, as appears by its title, at only unlawful restraints and monopolies. Congress did not intend to reach and destroy those minor contracts in partial restraint of trade which the long course of decisions at common law had affirmed were reasonable, and ought to be upheld.

The general language of the act is limited by the power which each individual has to manage his own property and determine the place and manner of its investment. Freedom of action in these respects is among the inalienable rights of every citizen.

A corporation, while by fiction of law recognized for some purposes as a person and for purposes of jurisdiction as a citizen, is not endowed with the inalienable rights of a natural person, but it is an artificial person, created and existing only for the convenient transaction of business.

Where, however, no individual investment is involved, but there is a combination by several individuals separately owning stock in two competing railroad companies engaged in interstate commerce, to place the control of both in a single corporation, which is organized for that purpose expressly, and as a mere instrumentality by which the competing railroads can be combined, the resulting combination is a direct restraint of trade by destroying competition, and is illegal within the meaning of the act of July 2, 1890.

A suit brought by the Attorney General of the United States to declare this combination illegal under the act of July 2, 1890, is not an interference with the control of the States under which the railroad companies and the holding company were, respectively, organized.

Source: Northern Securities Company v. the United States, 193 U.S. 197 (1904).