St. Clair County is the oldest county in the U.S. state of Illinois. According to the 2010 census, it had a population of 270,056, making it the eighth most populous county in Illinois and the most populous in the southern portion of the state. Its county seat is Belleville.
Latitude: 38° 28' 12.00" N
Longitude: -89° 55' 48.00" W
Nearest city to this article: Freeburg, Illinois Read about St. Clair County, Illinois in the Wikipedia Satellite map of St. Clair County, Illinois in Google Maps