Formed in the United States during World War II to provide air defense and combat training for the personnel of newly formed units, the Fourth Air Force was assigned, in turn, to Continental Air Forces, Air Defense Command, and Continental Air Command before inactivating in 1960. The Fourth Air Force served in the air defense program, 1966-1969 and became part of the Reserve program in 1976.

Commands During World War II

• IV Bomber Command 1941-44
• IV Fighter Command 1941-44
• IV Ground Air Support Command 1941-42