Although only one house stands today, the Mann-Simons Site was a collection of commercial and domestic spaces owned and operated by the same African-American family from at least 1843 until 1970. The property and its multiple buildings changed considerably over time to better accommodate the needs, tastes, and aspirations of this remarkable family. In 1970, through eminent domain, the Columbia Housing Authority acquired the site, leading to a grassroots preservation movement that saved the main house, which opened as a museum in 1978.