bill. The total cost of the two structures was now estimated at $14.25 million. The PWA bill passed Congress on June 25, 1938, (Public Law 75-723), and President Roosevelt signed it into law. Design Progress on construction was quite rapid. Design of the building was overseen by Louis A. Simon, the Supervising Architect in the Office of the Supervising Architect in the United States Department of the Treasury, which had oversight of all federal construction. The primary architect was Charles Zeller Klauder, a designer who worked in a variety of styles. 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. Because of the need to provide a great deal of interior light via windows, Klauder proposed a "fishbone" structure: A long central corridor from which five short, narrow wings projected on both the north and south sides. The overall length of the building was , and it had elements of both Streamline Moderne and Egyptian Revival in its facade. Klauder also proposed an alternative treatment of the building. He suggested making the three central wings look like pylons from the street, each with a low base. All the wings would have high windows, set apart with deep reveals. Pilasters high topped by non-load bearing lintels would help screen the bays created by the wings. The entire two-building structure would have a uniform cornice line, be five stories tall, have a limestone facade, and have of internal space (of which the railroad building had ). A two-story penthouse contained mechanical and HVAC systems. The commission was greatly pleased by Klauder's alternative treatment, and approved it on July 28, 1939. Detailed architectural and engineering designs were immediately begun. By November 1938, the cost of the two buildings had fallen to $10.815 million. Construction Construction of the two buildings proved very important to the District of Columbia. Prior to 1939, most federal office buildings were clustered in Federal Triangle or areas close to the White House. The District's building boom was driven in great part by the needs of the United States Department of War, which was adding tens of thousands of