On May 30, 1840, the Van Buren County Commissioners awarded a $6,500 contract for construction of a new courthouse in Keosauqua, which had edged out the village of Bentonsport in the county seat election two years prior. The courthouse was finished in September 1843, making it the oldest courthouse in Iowa to be in continuous operation since its opening date. A major interior restoration project was completed in 1983 and exterior improvements were made in 1997.

Though the main courthouse building has changed little since its initial construction, additional buildings have been added to the courthouse complex, including an additional county office constructed in 1896 (expanded in 1979) and a separate Law Enforcement Center built in 1993.