Additional barracks were constructed 1936–1937, and light bombers replaced pursuit and attack aircraft. World War II Barksdale was developed as an Air Corps flying school November 1940 and the runway apron was completed mid-1941. Between 23 and 25 May 1940, Barksdale Field was host to the Army's "complete military maneuvers" simulating European combat operations. Some 320 aircraft from throughout the Army Air Corps participated, as Major General Dwight D. Eisenhower watched. General George C. Marshall, the U.S. Army Chief of Staff, also briefly visited Barksdale Field during the latter stages of the maneuvers. During World War II, the airfield trained replacement crews and entire units between 1942 and 1945. Known units that trained at Barksdale were: 27th Bombardment Group (Light) 1 February 1940 – 7 October 1940 (Douglas A-24 Dauntless) 8th Pursuit Group 5 September 1941 – 7 October 1941 (Curtiss P-40 Warhawk) 46th Bombardment Group (Light) 2 February 1942 – 1 April 1942 (Douglas A-20 Havoc) 44th Bombardment Group (Heavy) February 1942 – July 1942 (Consolidated B-24 Liberator) 98th Bombardment Group (Heavy) February 1942 – 30 March 1942 (Consolidated B-24 Liberator) 92nd Bombardment Group (Heavy) 1 March 1942 – 26 March 1942 (Boeing B-17 Flying Fortress) 93rd Bombardment Group (Heavy) 1 March 1942 – 15 May 1942 (Consolidated B-24 Liberator) 90th Bombardment Group (Heavy) 17 May 1942 – 21 June 1942 (Consolidated B-24 Liberator) 17th Bombardment Group (Medium) 23 June 1942 – November 1942 (Martin B-26 Marauder) 95th Bombardment Group (Heavy) 15 June 1942 – 26 June 1942 (Boeing B-17 Flying Fortress) 100th Bombardment Group (Heavy): 18 June 1942 – 26 June 1942 (Boeing B-17 Flying Fortress) 319th Bombardment Group (Medium): 26 June 1942 – 8 August 1942 (Martin B-26 Marauder) 321st Bombardment Group (Medium) 26 June 1942 – 1 August 1942 (North American B-25 Mitchell) The 335th Bombardment Group (Medium) took over training duties as a permanent Operational Training Unit (OTU) on 17 July 1942 with Martin B-26 Marauders. On 1 May 1944, the 335th was replaced by the 331st U.S. Army Air Forces (USAAF) Base Unit as the OTU, being subsequently replaced by the 2621st USAAF Base Unit on 1 December 1945. The 2621st provided pilot training until 26 September 1947, when it was inactivated and replaced by the 2621st Air Force Base Unit. Also during World War II Barksdale played host to the major contingent of the Free French Air Forces and Nationalist Chinese aircrews. Postwar