Arlington Hall Station, Building No. 401, 4000 Arlington Boulevard, Arlington, Arlington County, Virginia

Significance: Building 401 is closely associated with the history of Arlington Hall Station as the headquarters of U.S. Army intelligence from 1942 to 1989. The building constituted part of the first major building program undertaken by the Army at Arlington Hall Station after acquisition of the property from Arlington Hall Junior College in 1942. The Army established its Signal Intelligence Service (SIS) at the former campus. The SIS had responsibility for cryptoanalysis of intercepted enemy messages, development of codes and ciphers for the Army, and production of Army cipher machines. The SIS scored several significant intelligence success during World War II, including the breaking of the Japanese military and diplomatic cipher systems. This work provided crucial intelligence information to Allied leaders. Since World War II, Army intelligence agencies have continued to be headquartered at Arlington Hall Station. Their activities are largely cloaked in secrecy. Building 401 is also significant as a massive example of the temporary military buildings erected throughout the United States during World War II. The building is of wood frame platform construction with asbestos Transite panels applied as siding. The entire building was erected within approximately ninety days.
Survey number: HABS VA-1270-V