Cryptologic History Calendar

1947: National Security Act Passed.

Wednesday, July 26, 2017

1947: National Security Act Passed.

Description: On 26 July 1947, President Truman signed the National Security Act of 1947. The Act mandated a major reorganization of the foreign policy and military establishments of the U.S. Government. The act created many of the institutions that Presidents found useful when formulating and implementing foreign policy, including the National Security Council (NSC).

The Council itself included the President, Vice President, Secretary of State, Secretary of Defense, and other members (such as the Director of the Central Intelligence Agency), who met at the White House to discuss both long-term problems and more immediate national security crises.

The act also established the Central Intelligence Agency (CIA), which grew out of World War II era Office of Strategic Services and small post-war intelligence organizations. The CIA served as the primary civilian intelligence-gathering organization in the government. Later, the Defense Intelligence Agency became the main military intelligence body. The 1947 law also caused far-reaching changes in the military establishment. The War Department and Navy Department merged into a single Department of Defense under the Secretary of Defense, who also directed the newly created Department of the Air Force. However, each of the three branches maintained their own service secretaries. In 1949 the act was amended to give the Secretary of Defense more power over the individual services and their secretaries.