In Railroad Company v. Maine, the Supreme Court of the United States was asked to decide whether a state could impose a tax on a railroad company for the privilege of operating 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 applied equally to 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. As such, the Court held that the tax was constitutional and could be imposed on the railroad company.

Justice Field delivered the dissenting opinion in Railroad Company v. Maine, arguing that the state of Maine had no authority to impose a tax on railroad companies operating within its borders. He argued that such taxation was unconstitutional because it violated Article I, Section 8 of the U.S Constitution which grants Congress exclusive power over interstate commerce and transportation networks between states. Furthermore, he argued that this type of taxation would be detrimental to interstate commerce as it could lead to multiple taxes being imposed by different states for goods traveling through their jurisdictions - creating an undue burden on businesses who must pay these taxes while also competing with each other in a free market economy. Finally, Justice Field stated that if individual states were allowed to impose such taxes then they would have too much control over interstate commerce and transportation networks which should remain under federal jurisdiction according to the Constitution's Commerce Clause.