On April 13, 1841, the county seat of Lake County was relocated and permanently established at Little Fort (now Waukegan) on the southeast quarter of Section 21 and county offices were accordingly moved from Burlington.
The courthouse moved from the 1968 Courts and Administration building into the new courthouse section in 1970. Additionally, the Jail was built on the back of the complex.
The Court Annex (previously the jail) was renovated and completed in 1998, adding six additional courtrooms and a large jury assembly room.
