He coauthored the Federalist Papers to promote the ratification of the Constitution, and several of his 29 essays (out of 85 total) became cornerstone texts of American political thought. Although initially skeptical of their necessity, Madison later drafted the first version of the Bill of Rights and guided it through the First Congress. As President Thomas Jefferson’s secretary of state, Madison negotiated and advocated for the 1803 Louisiana Purchase, which roughly doubled the size of the United States.
Madison served as president from 1809 to 1817, becoming America’s first president to declare war during the War of 1812. The war’s conclusion and the collapse of the Federalist Party reduced organized political opposition, ushering in the Era of Good Feelings, a brief period of relative national unity and one-party dominance. Despite believing that slavery violated revolutionary and republican ideals, Madison inherited and managed more than 100 slaves on his Virginia plantation.