United States Department of War ended in 1949.

United States Department of War was created in 1789.

The United States Department of War, also called the War Department (and occasionally War Office in the early years), was the United States Cabinet department originally responsible for the operation and maintenance of the United States Army. The War Department also bore responsibility for naval affairs until the establishment of the Navy Department in 1798 and for most land-based air forces until the creation of the Department of the Air Force in 1947. The Secretary of War headed the war department throughout its existence.

Joseph Franklin Siler has written:

'The Medical Department of the United States Army in the World War' -- subject(s): United States, United States. Army. Medical Department

The Department of Defense was once called the Department of War.