National Supremacy and the U.S. Constitution

Once written, the U.S. Constitution had to be ratified. To help this process, Federalists Alexander Hamilton, James Madison, and John Jay, using the pseudonym Publius, wrote a series of essays—The Federalist Papers—explaining the reasons for many of the policies and structures in the Constitution that people questioned. Federalist No. 44, written by Madison, examined the clauses in the Constitution that addressed restrictions on the authority of states and the supremacy of the federal government. The essay discussed such powers limited to the national government as coining money, making treaties with foreign countries, and raising an army. Madison then focused on the clause that deals with the supremacy of the U.S. Constitution.

The supremacy clause is the clause in Article 6 of the U.S. Constitution that establishes the U.S. Constitution as the supreme law of the land. Madison wrote that the "adversaries to the Constitution" did not want the national government to have this power, but without it Madison stated that the Constitution "would have been evidently and radically defective." Referring to the national government under the Articles of Confederation, Madison argued that, without this power, "the new Congress would have been reduced to the same impotent condition with their predecessors." As Madison notes in his conclusion to the essay, the question that is raised by challenging federal supremacy is "whether the Union itself shall be preserved."

While the Constitution clearly protects the rights of states, it does reserve to the federal government the final word when there are disagreements between federal and state law. This is known as federal preemption, a doctrine based on the supremacy clause of the U.S. Constitution, which holds that if there is a conflict between a higher law (federal) and lower law (state), federal law overrides state law.

In 1816 the state of Maryland attempted to tax a bank established by the federal government, stating that Congress did not have the right to establish the bank. An employee of the bank, James W. McCulloch, refused to pay the tax, resulting in a lawsuit. In McCulloch v. Maryland (1819) the U.S. Supreme Court ruled unanimously that the government did, in fact, have the authority to establish a bank. The decision was based on the necessary and proper clause, or elastic clause (Article 1, Section 8, Clause 18). Chief Justice John Marshall, writing the decision, held that the term necessary in the description of congressional authority meant that Congress could do whatever was "appropriate and legitimate" to carry out the tasks it was required to do. That included establishing a bank. Marshall also pointed out that, even though states had the power of taxation, that power did not hold precedent over the national government. This case and the Supreme Court's decision bolstered the supremacy of the national government.

Another significant challenge to federal supremacy came in 1824, in the form of a challenge to the commerce clause, Article 1, Section 8, Clause 3, of the Constitution, which grants Congress the authority to regulate both national and international commerce. New York had passed a law that identified people from other states as foreigners, making them subject to fees if they wanted to ship anything along New York waterways. Thomas Gibbons, a steamboat owner, operated a ferry service between New York and New Jersey. A competitor, Aaron Ogden, objected to Gibbons being given access to New York, and a New York court ruled that Ogden had an exclusive license to operate in New York coastal waters. Gibbons appealed the decision to the U.S. Supreme Court.

In Gibbons v. Ogden (1824), the U.S. Supreme Court held unanimously that the supremacy clause made the New York law invalid. Marshall stated that commerce included navigation on interstate waterways and that the right to regulate commerce in these waters belonged to Congress, not the state. Justice William Johnson added that his interpretation of the commerce clause was that the national government had the sole power over interstate commerce. This decision further established the supremacy of the federal government.