United States War Dept

The United States War Department was the executive department of the U.S. federal government responsible for military affairs from 1789 to 1947. Headed by the Secretary of War, it managed finance, purchases, and military operations until it was reorganized under the National Security Act of 1947 into the Department of the Army and Department of the Air Force. It produced numerous official reports, documents, and publications on military history and operations.[3]

Aug 7, 1789 Wikipedia
Military History Government Documents Official Reports