4th Air Force, Hamilton AFB, California

The 4th Air Force, originally established in 1940, is a numbered air force of the United States Air Force Reserve Command. During World War II, it was responsible for the air defense of the western United States and the training of bomber and fighter personnel. After various assignments and inactivations, the 4th Air Force was headquartered at Hamilton Air Force Base, California, from 1946 to 1966, focusing on air defense and reserve training missions during the Cold War. Today, the 4th Air Force oversees strategic airlift, air refueling, and aeromedical evacuation missions for the Air Force Reserve.