The Prince William County Courthouse on Lee Avenue is a mid-19th century building that has anchored the civic identity of Manassas since before the Civil War. The current structure dates largely from 1893, though the site has functioned as a courthouse since 1822. It is listed on the National Register of Historic Places.
The building is a working courthouse, not a museum, but its exterior and setting contribute significantly to the character of Old Town. It sits a short walk from the Manassas Museum and the train station, making it a natural stop on any circuit of the historic district.