In 1871, construction on the building began anew under the supervision of architect Alfred Mullett and it was finally completed ten years later. Its most prominent feature is considered by many to be its opulent Marble Hall. This Greek revival masterpiece includes 14 Corinthian columnns that depict Mercury and the goddess Luna bathed in natural light from the rooms massive sky light.
The building underwent its first major renovation in 1916 after the post office and federal courts were relocated. It experienced further renovations over the years. One in conjunction with the country's bicentennial in 1975-76 and another, conducted by the General Services Administration, in 1986. The U.S. Customs and Border Protection Agencies returned to the building in 2011 after being forced to leave after the building was damaged by Hurricane Katrina in 2005.
Today, the building is a tourist attraction but still holds offices of the Customs Service. Since 2008, the first floor of the building has been home to the Audubon Butterfly Garden and Insectarium, a museum that connects children and adults to the world of insects and is the largest museum of its kind in North America.