Fort Massac occupies a strategic Ohio River site in southern Illinois that served French colonial, early U.S., and frontier purposes over centuries. A French fort built there in 1757 during the French and Indian War, later renamed for the Marquis de Massiac, was abandoned after the war and destroyed sometime after 1763. The site regained importance in 1778 when George Rogers Clark entered Illinois nearby, and a new fort rose there in 1794 during the Northwest Indian War. Lewis and Clark stopped there in 1803, and Aaron Burr met James Wilkinson there in 1805. Damaged by the New Madrid earthquakes, the fort was repaired, decommissioned in 1814, and later preserved as Illinois’s first state park.