Robert Mills designed some of the nation's most prominent buildings, including the Washington Monument. Ainsley Hall, a wealthy Columbia merchant, hired Mills to plan the Columbia townhouse in 1823. Mills designed few private residences. The house reflects the architect's preference for the classical revival style, with a large portico dominating the north faade. Hall died before the house was finished.

The collection in the house displays decorative arts of the early 19th century, including American Federal, English Regency, and French Empire pieces. The basement contains service rooms with objects used for the storage and preparation of food.

The Robert Mills House survives as a testament of Mills' architectural ability. Tickets are available at the museum shop. The house is open Tuesday through Saturday from 10:00 a.m. to 3:00 p.m., and Sunday from 1:00 to 4:00 p.m.