In the 1946 case United States v. Pullman Company et al., the U.S Supreme Court ruled that The Pullman Company, a railroad car manufacturer and operator of sleeping cars on many railroads, was in violation of antitrust laws due to its monopolistic practices. The government argued that by manufacturing, operating and providing services for sleeper cars all at once, Pullman had created an unlawful monopoly which stifled competition within the industry. In response to these charges, Pullman contended it was not engaged in interstate commerce but rather provided public services under state regulation. However, this argument did not hold up as their operations were found to be part of a broader scheme affecting interstate commerce directly and substantially. Therefore, they fell within federal jurisdiction under the Sherman Antitrust Act - legislation designed to prevent anti-competitive business activities such as monopolies or cartels from forming.

In the dissenting opinion for United States v. Pullman Company et al., Justice Frankfurter argued that the majority's decision to dissolve the Pullman Company was an overreach of judicial power. He contended that such a drastic measure should be left to Congress, not decided by courts interpreting antitrust laws. The justice believed this case did not present a clear-cut violation of antitrust law and thus, it was inappropriate for the court to order dissolution without legislative guidance or precedent. Furthermore, he pointed out potential negative economic consequences from breaking up a company with significant influence in its industry like Pullman Company had at that time in railroad sleeping car services sector.