Historical Marker
Johnson County Courthouse
Historical marker location:
401 Court Street, Vienna, Illinois
( Marker can be reached from Court Street just west of South 4th Street, on the left when traveling west.)
Marker installed: 2010
1871 .
Illinois was part of the French colonial empire, and the city of Cahokia, located near present-day Collinsville, was one of the largest pre-Columbian cities in North America. At its peak, around 1250 CE, Cahokia had a population of around 20,000 people.