Fort Johnston

Historical marker location:

127 E Prospect Ave, Ottawa, Illinois

( Memorial is on East Prospect Avenue west of Catherine Street, on the right when traveling east.)

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.