The Old Market House, constructed in 1845-1846, was a center of Galena's community life during Galena's "Golden Era." The greek revival house sheltered vendors and shoppers, who gathered in the heart of the river city's business district until 1910. Ownership of the building was transferred to the State of Illinois in 1947, and the Old Market House was restored in 1955. Today the Old Market House State Historic Site is managed by the Illinois Historic Preservation Agency and is the scene of many changing exhibits, meetings and special events.

Visitors can view exhibits on the first floor of the Old Market House. Site interpreters describe aspects of the building's history and architecture. The first floor is disabled accessible; the second floor and basement are not. The grounds are used frequently for community events.