In the 1927 case Swift & Company et al. v. United States, the Supreme Court ruled in favor of the U.S., upholding a lower court's decision that Swift and several other meatpacking companies had violated anti-trust laws by conspiring to fix prices and control supplies in violation of the Sherman Antitrust Act. The defendants argued they were not engaged in interstate commerce as their activities were confined within individual states, hence outside federal jurisdiction. However, Justice Edward Terry Sanford writing for a unanimous court rejected this argument stating that although some actions may occur within one state's boundaries, if they are part of an overall scheme affecting interstate commerce then it falls under federal regulation. This ruling expanded federal power over business practices significantly.

In the dissenting opinion for Swift & Company et al. v. United States, Justice McReynolds argued that the majority's interpretation of the Sherman Act was too broad and exceeded its original intent. He contended that Congress did not intend to regulate all commerce activities but only those which directly affected trade among states or with foreign nations. The defendants' actions in this case, he believed, were local matters beyond federal jurisdiction under the Commerce Clause of Constitution as they involved mere purchase and slaughter of livestock within a single state before any interstate transaction occurred. Furthermore, he criticized the majority's reliance on future possibilities or probabilities rather than present facts to determine whether an activity constituted interstate commerce - a departure from established legal principles according to him.