Built between 1939 and 1940, using the design of architect Charles Z. Klauder and Louis A. Simon. Although intended for the Railroad Retirement Board, its first occupant was to the United States Department of War.
On July 28, 1938, Simon and Klauder presented their design for the two structures to the United States Commission of Fine Arts, which had the authority to review all new public buildings erected in the District of Columbia. Klauder designed back-to-back buildings, with the Social Security structure facing Independence Avenue SW and the Railroad Retirement building facing C Street SW. The finished building, in addition to its unusual "fishbone" plan, had elements of both Streamline Moderne and Egyptian Revival in its facade.
By Act of Congress, it was renamed the Mary E. Switzer Memorial Building on October 21, 1972, becoming the first federal building to be named for a woman.
DC Inventory: April 26, 2007
National Register: July 6, 2007