The B-47 medium bomber became the foundation of the Air Force's newly created Strategic Air Command, and many were adapted for several specialized functions. One became a missile carrier, others were reconnaissance aircraft or trainers or carried remote controls for other aircraft. Between 1947 and 1956, a total of 2,032 B-47s in all variants were built. Boeing built 1,373, Douglas Aircraft Co. built 274 and Lockheed Aircraft Corp. built 385.