The county was created in 1785 and Unionville was selected as the county seat. The first courthouse was built in 1791. County seat name was changed to Union. The second courthouse was designed by Robert Mills and constructed with native granite in 1827. The courthouse was torn down in 1910 for the construction of the second and present courthouse erected in 1911 to 1912.

The building is located on landscaped grounds in the center of Union. The building has a large semi circular portico with eight large columns rising to a roof with balustrade. The entrance is recessed and framed with windows above on the second story. There are panels between the first and second story windows. On the roof is a wide dome. The building houses the County Circuit Court, County Family Court, County Probate Court and County Magistrate Court of the 16th Judicial Circuit. The architect was Anthony Ten Eyck Brown and the contractor was John Jefferson Cain