Department of War

The Department of War was a U.S. government agency responsible for overseeing the country's military forces, primarily the Army, from 1789 to 1947. It managed military policies, operations, and personnel, acting as the main authority on national defense before being renamed the Department of Defense. Its role was to ensure the country’s security through military readiness and coordination. In 1947, the Department of War was merged into the broader Department of Defense, which now oversees all branches of the U.S. military, including the Army, Navy, Air Force, and Marines.