The Cahokia Courthouse State Historic Site is a reconstructed French-Canadian structure built about 1740 at what is now 107 Elm Street, Cahokia, Illinois. At various times it has served as a house and as a courthouse. It is currently interpreted to resemble its appearance about 1800 as a frontier courthouse of the Northwest Territory. The courthouse was listed on the National Register of Historic Places on November 9, 1972.Under the flag of FranceFollowing the explorations of Marquette, Jolliet and La Salle in the 1670s, the Mississippi Valley became part of New France. The adventurous French had mapped more territory than their numbers could settle, but their attention soon focused on a section of the valley south of the mouth of the Missouri River. In this region, which would later be known as the American Bottom, the alluvial soil was exceptionally fertile, and the local Native Americans, members of the Illiniwek nation or Illinois Confederacy, were friendly to the newcomers.In the early 18th century, French-speaking immigrants, mostly from Canada, settled villages in the American Bottom such as Kaskaskia, Prairie du Rocher, and Cahokia. They lived in harmony with the Indians and named several of their villages, such as Cahokia, after constituent tribes of the Illiniwek who lived nearby.
