Fort de Chartres was a French fortification first built in 1720 on the east bank of the Mississippi River in present-day Illinois. It was used as the administrative center for the province, which was part of New France. Due generally to river floods, the fort was rebuilt twice, the last time in limestone in the 1750s in the era of French colonial control over Louisiana and the Illinois Country. The magazine (ammunition storehouse) of the fort is believed to be the oldest surviving building in Illinois. A partial reconstruction now exists of the limestone fort and the site is preserved as an Illinois state park, four miles (6 km) west of Prairie du Rocher in Randolph County, Illinois. Located on the floodplain area that became known as the American Bottom, the site is south of modern St. Louis. The fort were placed on the National Register of Historic Places and recognized as a National Historic Landmark on October 15, 1966. It was named one of the contributing properties to the French Colonial Historic District in 1974, along with other area French-influenced sites such as the Creole House, the Pierre Menard House, the Kolmer Site (a former Indian village), and the site of Fort Kaskaskia. The name of the fort honored Louis, duc de Chartres, son of the Regent of France. The state historic site today hosts several large re-enactments at the fort of colonial-era civil and military life each summer. History French rule On January 1, 1718, the French government granted a trade monopoly to John Law and his Company of the West. Hoping to make a fortune mining precious metals, the company built a fort to protect its interests. The original wooden fort was built in 1718–1720 by a French contingent from New Orleans, led by Pierre Dugué de Boisbriant. When administration of the Illinois Country was moved from Quebec City to New Orleans, governance was transferred to the Company of the Indies. The fort was built to be the seat of government and to control the Indians of the region, particularly the Fox. The original fort was a palisade of logs with two bastions at opposite corners. Within five years, flooding from the Mississippi had left the original fort in bad condition. Construction of a second fort further from the river, but still on the flood plain, began in 1725. This fort was also made of logs and