In the case of Terminal Railroad Association of St. Louis et al. v. United States et al., 1924, the U.S Supreme Court ruled that a group of railroad companies violated antitrust laws by monopolizing access to St. Louis area railroads and bridges across the Mississippi River, thereby limiting competition in interstate commerce. The Terminal Railroad Association was formed by several major railway companies who jointly purchased all railways and bridges into St.Louis with an aim to control freight traffic in this region which was considered as one of America's busiest transportation hubs at that time. The court held that such consolidation constituted a restraint on trade because it prevented other carriers from entering or competing in the market without paying fees or obtaining permission from these controlling entities, thus violating Sherman Antitrust Act (1890). As per its ruling, instead of breaking up this association completely, it ordered for restructuring under supervision so as to allow equal access for all railroads wishing to use these facilities while maintaining efficiency benefits derived from unified operation.

In the dissenting opinion for Terminal Railroad Association of St. Louis v. United States, Justice McReynolds argued that the majority's decision to classify a private railroad terminal as a public utility subject to federal regulation was an overreach of government power. He contended that this ruling would set a dangerous precedent by allowing the government to regulate any business it deemed necessary for public use, even if it was privately owned and operated. Furthermore, he disagreed with the majority's interpretation of interstate commerce laws, asserting that they were not intended to give such broad regulatory powers to the federal government over private businesses operating within individual states.