Fort Kaskaskia State Historic Site preserves the bluff-top location of a colonial-era fortification built to defend Kaskaskia, one of the oldest and most important French villages in the Illinois Country, a farming and fur-trading community founded in the late seventeenth century along the Mississippi and Kaskaskia rivers. The French constructed an earthen and log fort on the bluff around 1759 as tensions from the French and Indian War increased, using it as a lookout and defensive redoubt overlooking the village and its agricultural fields below rather than as a major garrisoned post. After France ceded the region to Great Britain in 1763, British authorities showed little interest in the works and largely let them fall into disuse. Their strategic value re-emerged during the American Revolution when George Rogers Clark's Virginia militia captured Kaskaskia without a fight on July 4, 1778, and used the fort and village as a base of operations and supply point for the subsequent campaign that captured Vincennes and secured the Illinois Country for the United States. American forces held the position through the end of the war, and it passed formally to the United States under the 1783 Treaty of Paris. The village of Kaskaskia itself was later devastated by Mississippi River flooding in 1881, and the graves of its residents were relocated to a cemetery, Garrison Hill, within the historic site. Today the roughly 200-acre park preserves the eroded earthworks and offers an overlook of the historic Kaskaskia village site and river valley below.