The original section of this courthouse, completed in 1882 after the county seat moved to Walterboro from Jacksonborough, was built by contractor William Thompson. The front portico is attributed to Robert Mills, who completed an unfinished design by William Jay. The courthouse was in such poor condition within a few years, however, that it was extensively renovated in 1843-44.
This courthouse, listed in the National Register of Historic Places in 1971, is built of brick covered in stucco scored to imitate stone. It was enlarged in 1916 by a frame wing on the west elevation. In 1937-39 a project of the Works Progress Administration covered the west wing with brick, built a new brick wing on the east elevation and an addition on the north entrance, and remodeled the interior.