Southern Illinois Southern Illinois Southern Illinois (also known as "Little Egypt") is the southern third of the state of Illinois. The southern part of Illinois has a unique cultural and regional history. Part of downstate Illinois, the Southern Illinois region is bordered by the two most voluminous rivers in the United States: the Mississippi River and its connecting Missouri River to the west, and the Ohio River to the east and south with the Wabash as tributary. Southern Illinois' most populated city is Belleville at 44,478. Other principal cities include Alton, Centralia, Collinsville, Edwardsville, Effingham, O'Fallon, Harrisburg, Herrin, Mt. Vernon, Marion, and
Fox River (Illinois River tributary) near the Fox River included the Potawatomi, Sac, and Fox tribes. The Fox River has 15 dams, including McHenry Dam, which raises the river slightly to maintain depth in the Chain O'Lakes in northern Illinois, and a hydroelectric dam near Ottawa. In the winter, bald eagles can be found nesting along the banks. Early in the history of Illinois, the Fox River provided water for the Illinois and Michigan Canal via a feeder canal, allowing the canal to pass over the Fox River on an aqueduct. In 1996, a flood damaged the Farnsworth House in Illinois, a residence designed by