Constituted as the 40th Bombardment Group (Medium) on 22 Nov 1940. Activated in Puerto Rico on 1 Apr 1941. Redisgnated 40th Bombardment Group (Heavy) in May 1942. Patrolled the Canbbean and Pacific, using B~I7, B-18, and B-24 aircraft. Operated first from Puerto Rico and later from the Panama Canal Zone. Moved to the US in Jun 1943. Redesignated 40th Bombardment Group (Very Heavy) in Nov 1943. After training with B-29's, moved to India, via Africa, Mar-Jun 1944. Assigned to Twentieth Air Force in Jun 1944. Transported supplies over the Hump to staging bases in China before entering combat with a strike on railroad shops at Bangkok, Thailand, on 5 Jun 1944. On 15 Jun 1944 participated in the first AAF attack on Japan since the Doolittle raid in 1942. Operating from bases in India, and at times staging through fields in China, the Group struck such targets as transportatIon centers, naval installations, iron works, and aircraft plants in Burma, Thailand, China, Japan, Indonesia, and Formosa, receiving a Distinguished Unit Citation for bombing iron and steel works at Yawata, Japan, on 20 Aug 1944. From a staging field in Ceylon, it mined waters near the port of Palembang, Sumatra, in Aug 1944. Moved to Tinian, Feb to Apr 1945, for further operations against Japan. Made daylight attacks from high altitude on strategic targets, participated in incendiary raids on urban areas, and dropped mines in Japanese shipping lanes. Received a Distinguished Unit Citation for attacking naval aircraft factories at Kure, oil storage facilities at Oshima, and the industrial area of Nagoya, in May 1945. Bombed light metal industries at Osaka in Jul 1945, being awarded another Distinguished Citation for this mission. After V-J Day, dropped food and supplies to Allied prisoners in Japan, Korea, and Formosa, and took part in show-of-force missions. Returned to the United States in Nov 1945. Assigned to Strategic Air Command on 21 Mar 1946. Inactivated on I Oct 1946.

SQUADRONS

STATIONS

Borinquen Field, Puerto Rico	1	Apr	1941
Howard Field, Canal Zone	16	Jun	1942
Albrook Field, Canal Zone	16	Sep	1942
Howard Field, Canal Zone	3	Jun	1943
Pratt Army Air Field, Kansas	1	Jul	1943 to 12 Mar 1944
Chakulia. India	2	Apr	1944 to 25 Feb 1945
Tinian, Marianas	4	Apr	1945 to 7 Nov 1945
March Field, California	27	Nov	1945
Davis-Monthan Field, Arizona	8	May	1946 to 1 Oct 1946

COMMANDING OFFICERS

Lt. Col. William B. Sousa	1 Apr 1941
Maj. George W. McGregor 29 Apr	1941
Col. Ivan M. Palmer	26 Nov 1941
Col. Vernon C. Smith 19 Jan	1943
Col. Henry K. Mooney 16 May	1943
Col. Lewis R. Parker	1 Jul 1943
Lt. Col. Louis E. Coira 24 Feb	1944
Col. Leonard F. Harman 10 Apr	1944
Col. William H. Blanchard	4 Aug 1944
Col. Henry R. Sullivan 16 Feb	1945
Col. William K. Skaer 27 Feb	1945
Lt. Col. Oscar R. Schaaf	21 Mar 1946
Col. Alva L. Harvey	4 May 1946
Lt. Col. Oscar R. Schaaf	21 Aug 1946
1st Lt. William F. Seith	21 Sep to 1 Oct 1946

CAMPAIGNS

Anti-Submarine, American Theater
India-Burma
China Defensive
Western Pacific
Central Burma
Air Offensive, Japan