On April 29, 1825, Revolutionary War hero Marquis de Lafayette visited St. Louis as part of his yearlong, 6,000-mile Farewell Tour across all 24 U.S. states. St. Louis, the westernmost stop, welcomed Lafayette with great fanfare, including a grand ball at the Mansion House Hotel—hailed as the finest party in the city’s history. Public historian Amanda Clark explains how, though brief, Lafayette’s visit was a defining moment in St. Louis’s early identity.