Commerce succeeds to manufacture, and is not a part of it. The power to regulate commerce is the power to prescribe the rule by which commerce shall be governed, and is a power independent of the power to suppress monopoly. But it may operate in repression of monopoly whenever that comes within the rules by which commerce is governed or whenever the transaction is itself a monopoly of commerce. The regulation of commerce applies to the subjects of commerce, and not to matters of internal police. Contracts to buy, sell, or exchange goods to be transported among the several States, the transportation and its instrumentalities, and articles bought, sold, or exchanged for the purposes of such transit among the States, or put in the way of transit, may be regulated, but this is because they form part of interstate trade or commerce.
Manufacture is transformation the fashioning of raw materials into a change of form for use.
The functions of commerce are different. The buying and selling and the transportation incidental thereto constitute commerce, and the regulation of commerce in the constitutional sense embraces the regulation at least of such transportation. . . . If it be held that the term includes the regulation of all such manufactures as are intended to be the subject of commercial transactions in the future, it is impossible to deny that it would also include all productive industries that contemplate the same thing. Slight reflection will show that, if the national power extends to all contracts and combinations in manufacture, agriculture, mining, and other productive industries whose ultimate result may affect external commerce, comparatively little of business operations and affairs would be left for state control. The object was manifestly private gain in the manufacture of the commodity, but not through the control of interstate or foreign commerce.