In Railroad Company v. Maryland, the Supreme Court of the United States was asked to decide whether a state could impose a tax on a railroad company that operated within its borders. The railroad company argued that the tax was unconstitutional because it violated the Commerce Clause of the United States Constitution. The Court held that the tax was constitutional because it was a valid exercise of the state's power to tax and regulate businesses within its borders. The Court also held that the tax did not violate the Commerce Clause because it was not discriminatory against interstate commerce. The Court reasoned that the tax was not discriminatory because it was imposed on all railroads operating within the state, regardless of whether they were engaged in interstate or intrastate commerce. The Court also noted that the tax was not excessive and did not place an undue burden on interstate commerce. The Court concluded that the tax was a valid exercise of the state's power to tax and regulate businesses within its borders and did not violate the Commerce Clause.

Justice Field delivered the dissenting opinion in Railroad Company v. Maryland, arguing that the state of Maryland had no right to impose a tax on railroad companies operating within its borders. He argued that such taxes were unconstitutional because they interfered with interstate commerce and violated the Commerce Clause of the Constitution. Furthermore, he argued that Congress alone had authority over interstate commerce and any attempt by states to regulate it was an infringement upon federal power. He also noted that if states could levy taxes on railroads then other businesses would be subject to similar taxation which would lead to chaos as each state attempted to control all aspects of business operations within their borders. Finally, Justice Field concluded his dissent by noting that while some regulation may be necessary for public safety or health reasons, this case did not involve those issues and thus should have been decided differently than it was by majority opinion.