Until the 1940s, Senate staff positions were mostly clerical and custodial. President Franklin Roosevelt's New Deal and the response to the nation's entry into the Second World War fueled the growth and domination of the executive branch. As a result, congressional leaders became convinced of the need to greatly expand their staffs to include experts on a growing list of complex policy issues.
Soon after the war ended, Congress passed the Legislative Reorganization Act of 1946. This landmark statute allowed Congress to hire professional staffs at salaries equal to those employed by the executive branch. Each committee gained four professional and six clerical aides. The surge in numbers of new staff made a second building necessary - one intended primarily to accommodate committees.
In a departure from committee arrangements in the Russell Building, where members and witnesses sat around a common table, the new building would feature large hearing rooms with raised platforms for members and facilities suitable for the new medium of television.