In the case of Swift & Co. v. United States (196 U.S. 375, 398 (1905)), the Federal government sued a meat trust for being an unlawful economic monopoly.  The US Supreme Court held that Congressional power under the Interstate Commerce Clause justified regulations of the meat trust. The Court held that the effect of the trust on commerce among states was not "accidental, secondary, remote or merely probable," but rather a direct attempt to monopolize commerce. Business done at the stockyards was found to be one part of a continuous stream of commerce.

• The Court drew a distinction between manufacturing monopolies, which had only indirect effects on commerce, and sales monopolies, which had direct and intended effects on commerce.
• Compare to United States v. E.C. Knight Co. (156 U.S. 1 (1895)).