In Wabash, St. Louis & Pacific Railway Company v. Knox, the Supreme Court of the United States was asked to decide whether a state law that prohibited railroads from charging more than two cents per mile for passenger fares was constitutional. The railroad argued that the law violated the Commerce Clause of the Constitution, which gives Congress the power to regulate interstate commerce. The Court held that the law was unconstitutional because it interfered with the power of Congress to regulate interstate commerce. The Court reasoned that the law was an attempt to regulate interstate commerce, which was beyond the power of the state. The Court also noted that the law would have a negative effect on interstate commerce, as it would make it more difficult for railroads to compete with other forms of transportation. The Court concluded that the law was an unconstitutional interference with Congress' power to regulate interstate commerce and struck it down. This decision established the principle that states cannot pass laws that interfere with Congress' power to regulate interstate commerce.

Justice Field delivered the dissenting opinion in Wabash, St. Louis & Pacific Railway Company v. Knox, arguing that Congress had not intended to limit the power of state courts when it passed the Interstate Commerce Act (ICA). He argued that while Congress had granted exclusive jurisdiction over certain matters related to interstate commerce to federal courts, this did not mean they were precluded from exercising their traditional powers in other areas. Furthermore, he noted that if states were prevented from exercising their authority over such matters as contracts and torts involving interstate commerce then there would be no effective way for citizens who have been wronged by companies engaged in such activities to seek redress. As a result, Justice Field concluded that allowing state courts to exercise concurrent jurisdiction with federal ones was necessary for justice and fairness and should be allowed under the ICA unless specifically prohibited by Congress.