workers. Roosevelt had adopted a policy of mobilization, to prepare the nation for possible entry into World War II. But most military officers and upper-level civilian workers lived in Northwest Washington and the Virginia counties across the Potomac River from it. To ensure that these tens of thousands of War Department workers could get to their jobs quickly and easily, War Department office buildings were planned for the northwest section of the city. This left no room for the Social Security and Railroad Retirement Board buildings in that part of town. Because workers for the Social Security Administration and the Railroad Retirement Board were low-wage workers without an urgent need to get to their jobs in a timely fashion, the Social Security and Railroad Retirement Board buildings were deliberately sited in Southwest Washington. This started a trend of federal construction of office buildings in Southwest Washington, leading to the creation of Southwest Federal Center. The Railroad Retirement Board Building and the Social Security Administration Building were the first federal office buildings constructed in Southwest D.C. Construction speed-up and defense assignment Construction on the two structures began in May 1939. Both the American Federation of Labor (AFL) and the Congress of Industrial Organizations (CIO) agreed not to strike contractors working on the two buildings. By July 1939, the cost of the two buildings was estimated to be $12 million. The foundations were complete by the end of the year, and President Roosevelt proposed in January 1940 to spend $3.25 million to continue work on the structures in coming year to reach a planned January 1, 1941, opening date. However, by June 1940, the space shortage affecting the War Department was so acute that PWA officials began speeding up construction on the Railroad Retirement Board Building. Already, rumors were swirling around Washington that the War Department, not the retirement board, would occupy the structure. These rumors proved true on June 20, 1940, when the PWA announced that the War Department was now slated to occupy both structures. Congress initially appropriated an extra $100,000 to pay for overtime and accelerated purchase of construction costs. An additional $400,000 was appropriated to further speed construction. The talks with contractors over speeding up construction proved effective, and the new deadline for completion of both buildings was fall of 1940. Agencies scheduled to take up residency in the two buildings included the National Defense Advisory Commission (an