U.S. manufacturer of jet fighters, commercial aircraft, and space vehicles. It was formed in the 1967 merger of the McDonnell Aircraft Co. (founded 1939) and the Douglas Co. (1921). During World War II, Douglas contributed 29,000 warplanes, one-sixth of the U.S. airborne fleet. After the war, it dominated commercial air routes with its DC-6 and DC-7. With the development of commercial jets, Douglas began to lag behind Boeing Co. and sought a merger with McDonnell, which had grown quickly during World War II and had continued to be a major defense supplier, designing the first carrier-based jet fighter. After the merger McDonnell Douglas produced widely used jet fighters (including the F-4 Phantom, A-4 Skyhawk, F-15 Eagle, and F-18 Hornet) as well as launch vehicles and cruise missiles. It was bought by Boeing in 1997. See also Lockheed-Martin