The United States Supreme Court case of United States v. Realty Company concerned the power of the federal government to tax the income of a real estate company. The company had been formed in 1868 and was owned by a group of individuals. The company had been formed to purchase and manage real estate in the District of Columbia. The company had been paying taxes on its income since 1868, but in 1872, the company stopped paying taxes on its income. The United States government then sued the company for the unpaid taxes. The Supreme Court held that the federal government had the power to tax the income of the real estate company. The Court reasoned that the power to tax was an inherent power of the federal government and that the company was subject to the federal government's taxing power. The Court also held that the company was not exempt from taxation because it was owned by individuals. The Court noted that the company was a separate entity from its owners and that it was subject to the same taxation as any other business. The Court's decision in United States v. Realty Company established the federal government's power to tax the income of businesses, regardless of who owns them. This decision has been cited in numerous cases since then, and it remains an important precedent in the area of taxation.

In the case of United States v. Realty Company, Justice Field delivered a dissenting opinion in which he argued that Congress had no power to pass legislation requiring the defendant to pay taxes on its property. He reasoned that since taxation was an inherent right of sovereignty and could not be delegated by one government to another, it followed that Congress did not have the authority to impose such a tax without violating the Constitution's prohibition against delegating legislative powers. Furthermore, he argued that if Congress were allowed this type of power then it would open up a dangerous precedent for future cases where other governments may attempt similar actions with respect to their own citizens or property within their jurisdiction. In conclusion, Justice Field concluded that any law passed by Congress attempting to levy taxes on private individuals or corporations must be declared unconstitutional as it is beyond its scope and violates fundamental principles of our constitutional system.