when did the war department change its name
United States Department of War The War Department existed from August 7, 1789[1] until September 18, 1947, when it split into Department of the Army and Department of the Air Force and joined the Department of the Navy as part of the new joint National Military Establishment (NME), renamed the United States Department of Defense in 1949.
Military justice The United States Constitution authorized the creation of a system of military justice. Article I, Section 8 permits the U.S. Congress to "make rules for the government and regulation of the land and naval forces."[26] Congress issued these rules first in 1806 as the Articles of War. Military justice during the American Civil War was governed by the 1863 Lieber Code. The Articles of War were superseded in 1951 by the Uniform Code of Military Justice (UCMJ).