It was built beginning in 1930, to house the expanded offices of the
United States Department of Agriculture (USDA). Construction was completed on the
U.S. Department of Agriculture Administration Building to the north of
Independence Avenue in 1930, but
Depression-era agriculture programs demanded far more office space than the main building could provide. The phased construction was completed in 1936. The building was added to the
National Register of Historic Places in 2007. The building's design is credited to
Louis A. Simon of the Federal
Office of the Supervising Architect. The South Building was joined to the Administration Building by two enclosed
pedestrian bridges spanning
Independence Avenue, thus consolidating USDA operations into one complex. The single-span stone arches form a dramatic accent on Independence Avenue. The
soffits of the bridges are faced with
Guastavino tile. The east bridge is dedicated to
Seaman A. Knapp, while the west bridge commemorates Agriculture Secretary
James Wilson. The new building contained laboratory space as well as offices. It was originally referred to as the "Extensible Building", which could be expanded in a phased fashion. The architecture of the South Building is a stripped-down example of
Classicism, with plain detailing that borrows from Classical form and proportion without using a great deal of expensive and time-consuming detail. The style became popular for government buildings until the advent of the
Modern style in government architecture, reaching its apex at the Pentagon. In the case of the South Building, the lesser level of detail indicated its subordinate position vis-à-vis the Administration Building. The interior is based on a rigidly-enforced network of corridors; only the departmental auditorium and library deviate from the corridor grid. Interiors are even more plain than the exterior. Since the relocation of laboratory space to the
Beltsville Agricultural Research Center, the South Building has been occupied exclusively by offices. ==See also==