This case was a dispute between the St. Louis, Iron Mountain & Southern Railway Company and the Railroad Commissioners of the State of Arkansas. The Railway Company argued that the Railroad Commissioners had no authority to regulate the rates of freight and passenger traffic on the Railway Company's lines. The Railway Company argued that the Railroad Commissioners had exceeded their authority by attempting to regulate the rates of freight and passenger traffic on the Railway Company's lines. The Supreme Court held that the Railroad Commissioners had exceeded their authority by attempting to regulate the rates of freight and passenger traffic on the Railway Company's lines. The Court held that the power to regulate the rates of freight and passenger traffic on the Railway Company's lines was vested in the Railway Company itself, and not in the Railroad Commissioners. The Court further held that the Railroad Commissioners had no authority to interfere with the Railway Company's right to set its own rates. The Court's decision was a victory for the Railway Company, as it affirmed the Railway Company's right to set its own rates for freight and passenger traffic on its lines. The decision also established the principle that the power to regulate the rates of freight and passenger traffic on a railway line is vested in the railway company itself, and not in the state.

In St. Louis, Iron Mountain & Southern Railway Company v. Berry & Another, Railroad Commissioners, the Supreme Court was asked to decide whether a state railroad commission had the authority to set maximum rates for freight and passenger transportation within its jurisdiction. The majority opinion held that it did not have such power under existing law; however Justice Field dissented from this ruling on several grounds. He argued that Congress had given states broad powers over interstate commerce in order to protect local interests and prevent monopolies from forming; thus he believed that the commission should be allowed to regulate intrastate rates as well as interstate ones in order to ensure fair competition between railroads operating within their borders. Furthermore, he noted that if states were unable or unwilling to exercise their regulatory powers then they would be powerless against any abuses of monopoly power by large corporations operating across multiple jurisdictions - something which could lead ultimately lead them into economic ruin due largely through no fault of their own. As such, Justice Field concluded his dissent with an appeal for greater federal oversight of interstate commerce so as better protect both consumers and small businesses alike from unfair practices by powerful corporate entities