Though these houses were built of brick and other longer-lasting materials, none remained single family homes by the 21st century, although some had been converted for other uses, such as office space. The Brennan House at 631 S. Fifth, which is operated as a historic property with daily tours, shows a glimpse of Downtown Louisville's residential past. A structure at 432 South Fifth Street is the only example of a pre-Civil War residence remaining Downtown; built in 1829 it has been converted to commercial use.