312th Bombardment Group (312th BG) "Roarin' 20's"
U.S. Army Air Force (USAAF), 5th Air Force (5th AF)

Background
During World War II, the 312th Bombardment Group (312th BG) was part of the U.S. Army Air Force (USAAF), 5th Air Force (5th AF). Initially formed as the 312th Bombardment Group (Dive) but rapidly transitioned into a light attack group operating the A-20 Havoc. Nickname "Roarin' 20's" or The "Roarin' 20's" by the middle of 1944. Each squadron used the suit from playing cards as their rear fuselage motif: 368th BS club, 387th BS diamond, 388th BS heart and 389th BS spade.

386th Bombardment Squadron (386th BS)
Established as the 386th Bombardment Squadron (Dive) in the United States then sent overseas to the South West Pacific Area (SWPA).

387th Bombardment Squadron (387th BS)
Established as the 386th Bombardment Squadron (Dive) in the United States then sent overseas to the South West Pacific Area (SWPA).

388th Bombardment Squadron (388th BS)
Established as the 386th Bombardment Squadron (Dive) n the United States then sent overseas to the South West Pacific Area (SWPA).

389th Bombardment Squadron (389th BS)
Established as the 386th Bombardment Squadron (Dive) in the United States then sent overseas to the South West Pacific Area (SWPA).

References
Combat Squadrons of the Air Force World War II (1982) pages 477 [PDF pages 489]

References
Dominator (1984) details the 386th BS use of the B-32 Dominator during 1945
The Roarin' 20's A History of the 312th Bombardment Group (1994) details 312th Bomb Group history
Helluva Pelican (1995) details A-20G "Hell'N Pelican II" 42-86786 from 388th BS
312th Bombardment Group (312th BG) DVD (2000)
Echoes of the Dominator (2007) details the 386th BS use of the B-32 Dominator during 1945
Rampage of the Roarin' 20's (2009) details 312th Bomb Group history detailing the entire unit history, veterans and aircraft