Article I, Section 8, Clause 3:
[The Congress shall have Power . . .] To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes; . . .
In this respect, the Swift case only states what the Shreveport case was later to declare more explicitly, and the same may be said of an ensuing series of cases in which combinations of employees engaged in such intrastate activities as manufacturing, mining, building, construction, and the distribution of poultry were subjected to the penalties of the Sherman Act because of the effect or intended effect of their activities on interstate commerce. 1