He then served as an artillery officer in the American Revolutionary War, where he saw military action against the British in the New York and New Jersey campaign, served for years as an aide to General George Washington, and helped secure American victory at the climactic Siege of Yorktown. After the Revolutionary War, Hamilton served as a delegate from New York to the Congress of the Confederation in Philadelphia. He resigned to practice law and founded the Bank of New York. In 1786, Hamilton led the Annapolis Convention to replace the Articles of Confederationwith the Constitution of the United States, which he helped ratify by writing 51 of the 85 installments of The Federalist Papers.

Jefferson and Aaron Burr tied for the presidency in the electoral college and, despite philosophical differences, Hamilton endorsed Jefferson over Burr, whom he found unprincipled. When Burr ran for governor of New York in 1804, Hamilton again campaigned against him, arguing that he was unworthy. Taking offense, Burr challenged Hamilton to a duel. In the July 11, 1804, duel in Weehawken, New Jersey, Burr shot Hamilton in the stomach. Hamilton was immediately transported to the home of William Bayard Jr. in Greenwich Village for medical attention, but succumbed to his wounds the following day.