The Douglas A-20 "Havoc" played an important role in the early part of World War II. The Army Air Corps became interested in the aircraft in 1939 and went on to order more than 6,000 aircraft in seven production models. Many of the Air Corps A-20's were delivered as Lend Lease aircraft with large numbers going to Great Britain and the Soviet Union. The A-20 remained in service with the Army Air Force throughout WW II; however, the improved Douglas A-26 "Invader" gradually replaced the A-20 as the AAF's primary twin-engine attack aircraft.
Information courtesy of the USAF Museum Archives.