It is an outstanding example of a public building and reflects the time when Charleston was one of the country's busiest port cities.
Marble is used throughout the building and highlighted in details such as office fireplaces.
The interior of the building revolves around a two-story center room, called the Business Room. Fourteen Corinthian columns support its second floor gallery, and most offices open onto this room. The ceiling is ornamented with artificial sky lights, a depiction of the American flag and other patriotic symbols, and stenciled classical motifs. Prior to the construction of the Custom House, port business was transacted in the Exchange . In need of larger facilities, this site between East Bay and the Cooper River was purchased by Congress in 1849.