Between 600-1200, this site was home to Effigy Mounds built by Native American people during the Woodland period, including seven mounds in geographic shapes and one giant turtle mound. The earthen mounds were lost under new development beginning in the 1840s, and none remain today. After Waukesha separated from Milwaukee County in 1846, a jail was built here in 1847 and the first Waukesha County Courthouse was completed in 1849. As the community grew, the courthouse ran out of room and an office building was added in 1860. Continued county growth in the late 19th century led to construction of a new courthouse in 1893, designed by Milwaukee architects Rau and Kirsch in the Richardsonian Romanesque style with local Lannon stone matching the rebuilt 1885 jail. In 1914, the courthouse became home to the Waukesha County Historical Society & Museum. A connector between the courthouse and jail was completed in 1938 through a Works Progress Administration project in the industrialist style with some Art Deco detailing. In 1959, the county courts, departments, and jail moved to a larger site on Moreland Boulevard, though some county departments remained and the Southeastern Wisconsin Regional Planning Commission rented parts of the building for many years. In 2002, the Waukesha County Historical Society & Museum purchased the complex. From 2015-2018, Historic Prairieville Ltd. rehabilitated the entire complex for adaptive reuse, and after full restoration it became home to Historic Courthouse 1893, the Martin Street Apartments, and the Waukesha County Historical Society & Museum.