Melville Fuller,
United States v. E. C. Knight Company…
“ 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. ”
