The Williamson County Historical Society seeks to preserve and share the history of Williamson County, Illinois. To this end, the society operates a museum of local history, housed within the 1916 jail and sheriff's residence. Rooms are set to period appearance. Settings include domestic spaces, a garment shop, a doctor's office, a country store, and a schoolroom. A military exhibit is also located on site.

The society offers period rooms, exhibits, one-hour museum tours, research library access, and research assistance. A fee is charged for research conducted on request.