United States Department of War

The United States Department of War was the federal government agency responsible for overseeing the U.S. Army and military affairs until 1947. It managed military planning, logistics, personnel, and operations, functioning as a key branch of national defense. In 1947, it was renamed the Department of Defense, reflecting the broader scope of coordinating all military services—Army, Navy, Air Force, and Marines—under one department. The department played a crucial role in shaping U.S. military strategy and policy during its existence, contributing significantly to the nation’s defense infrastructure.