Mr. Justice DAY delivered the opinion of the Court.

A bill was filed in the United States District Court for the Western District of North Carolina by a father in his own behalf and as next friend of his two minor sons, one under the age of fourteen years and the other between the ages of fourteen and sixteen years, employes in a cotton mill at Charlotte, North Carolina, to enjoin the enforcement of the act of Congress intended to prevent interstate commerce in the products of child labor. Act Sept. 1, 1916, 39 Stat. 675....

The attack upon the act rests upon three propositions: First: It is not a regulation of interstate and foreign commerce; second: It contravenes the Tenth Amendment to the Constitution; third: It conflicts with the Fifth Amendment to the Constitution.

The controlling question for decision is: Is it within the authority of Congress in regulating commerce among the states to prohibit the transportation in interstate commerce of manufactured goods, the product of a factory in which, within thirty days prior to their removal therefrom, children under the age of fourteen have been employed or permitted to work, or children between the ages of fourteen and sixteen years have been employed or permitted to work more than eight hours in any day, or more than six days in any week, or after the hour of 7 o'clock p. m., or before the hour of 6 o'clock a. m.?

The power essential to the passage of this act, the government contends, is found in the commerce clause of the Constitution which authorizes Congress to regulate commerce with foreign nations and among the states.

In Gibbons v. Ogdon, Chief Justice Marshall, speaking for this court, and defining the extent and nature of the commerce power, said, 'It is the power to regulate; that is, to prescribe the rule by which commerce is to be governed.' In other words, the power is one to control the means by which commerce is carried on, which is directly the contrary of the assumed right to forbid commerce from moving and thus destroying it as to particular commodities. But it is insisted that adjudged cases in this court establish the doctrine that the power to regulate given to Congress incidentally includes the authority to prohibit the movement of ordinary commodities and therefore that the subject is not open for discussion. The cases demonstrate the contrary. They rest upon the character of the particular subjects dealt with and the fact that the scope of governmental authority, state or national, possessed over them is such that the authority to prohibit is as to them but the exertion of the power to regulate....

In each of these instances the use of interstate transportation was necessary to the accomplishment of harmful results. In other words, although the power over interstate transportation was to regulate, that could only be accomplished by prohibiting the use of the facilities of interstate commerce to effect the evil intended.

This element is wanting in the present case. The thing intended to be accomplished by this statute is the denial of the facilities of interstate commerce to those manufacturers in the states who employ children within the prohibited ages. The act in its effect does not regulate transportation among the states, but aims to standardize the ages at which children may be employed in mining and manufacturing within the states. The goods shipped are of themselves harmless. The act permits them to be freely shipped after thirty days from the time of their removal from the factory. When offered for shipment, and before transportation begins, the labor of their production is over, and the mere fact that they were intended for interstate commerce transportation does not make their production subject to federal control under the commerce power.

Commerce 'consists of intercourse and traffic ... and includes the transportation of persons and property, as well as the purchase, sale and exchange of commodities.' The making of goods and the mining of coal are not commerce, nor does the fact that these things are to be afterwards shipped, or used in interstate commerce, make their production a part thereof.

Over interstate transportation, or its incidents, the regulatory power of Congress is ample, but the production of articles, intended for interstate commerce, is a matter of local regulation....

It is further contended that the authority of Congress may be exerted to control interstate commerce in the shipment of childmade goods because of the effect of the circulation of such goods in other states where the evil of this class of labor has been recognized by local legislation, and the right to thus employ child labor has been more rigorously restrained than in the state of production. In other words, that the unfair competition, thus engendered, may be controlled by closing the channels of interstate commerce to manufacturers in those states where the local laws do not meet what Congress deems to be the more just standard of other states.

There is no power vested in Congress to require the states to exercise their police power so as to prevent possible unfair competition. Many causes may co-operate to give one state, by reason of local laws or conditions, an economic advantage over others. The commerce clause was not intended to give to Congress a general authority to equalize such conditions. In some of the states laws have been passed fixing minimum wages for women, in others the local law regulates the hours of labor of women in various employments. Business done in such states may be at an economic disadvantage when compared with states which have no such regulations; surely, this fact does not give Congress the power to deny transportation in interstate commerce to those who carry on business where the hours of labor and the rate of compensation for women have not been fixed by a standard in use in other states and approved by Congress.

The grant of power of Congress over the subject of interstate commerce was to enable it to regulate such commerce, and not to give it authority to control the states in their exercise of the police power over local trade and manufacture.

The grant of authority over a purely federal matter was not intended to destroy the local power always existing and carefully reserved to the states in the Tenth Amendment to the Constitution.

Police regulations relating to the internal trade and affairs of the states have been uniformly recognized as within such control.... '

That there should be limitations upon the right to employ children in mines and factories in the interest of their own and the public welfare, all will admit. That such employment is generally deemed to require regulation is shown by the fact that the brief of counsel states that every state in the Union has a law upon the subject, limiting the right to thus employ children. In North Carolina, the state wherein is located the factory in which the employment was had in the present case, no child under twelve years of age is permitted to work.

It may be desirable that such laws be uniform, but our federal government is one of enumerated powers; 'this principle,' declared Chief Justice Marshall in McCulloch v. Maryland, 'is universally admitted....'

In interpreting the Constitution it must never be forgotten that the nation is made up of states to which are entrusted the powers of local government. And to them and to the people the powers not expressly delegated to the national government are reserved.... To sustain this statute would not be in our judgment a recognition of the lawful exertion of congressional authority over interstate commerce, but would sanction an invasion by the federal power of the control of a matter purely local in its character, and over which no authority has been delegated to Congress in conferring the power to regulate commerce among the states....

Mr. Justice HOLMES, dissenting.

The single question in this case is whethe Congress has power to prohibit the shipment in interstate or foreign commerce of any product of a cotton mill situated in the United States, in which within thirty days before the removal of the product children under fourteen have been employed, or children between fourteen and sixteen have been employed more than eight hours in a day, or more than six days in any week, or between seven in the evening and six in the morning. The objection urged against the power is that the States have exclusive control over their methods of production and that Congress cannot meddle with them, and taking the proposition in the sense of direct intermeddling I agree to it and suppose that no one denies it. But if an act is within the powers specifically conferred upon Congress, it seems to me that it is not made any less constitutional because of the indirect effects that it may have, however obvious it may be that it will have those effects, and that we are not at liberty upon such grounds to hold it void....

Mr. Justice McKENNA, Mr. Justice BRANDEIS, and Mr. Justice CLARKE concur in this opinion.