None. Dedicated bombers are exclusively the domain of the Air Force. Fighter/Bombers and attack aircraft can be found in the Air Force, Navy, and Marines. The US Army has no such aircraft.
Lesley McNair
LTC Jimmy Doolittle had 16 US Army B-25 Mitchell twin engine medium bombers. Heavy bombers had four engines.
Miller
Aug 6, '45 - Hiroshima and Aug 9 - Nagasaki Not dropped by US troops but by USAAF ( Army Air Forces ) bombers.
buzzard
3 u.s bombers disapeared during world war 2
US Army General Doolittle's "Raid on Tokyo" in 1942. Sixteen B-25 Mitchells (US Army) medium bombers (twin engined) launched from the deck of the fleet aircraft carrier, USS Hornet (later sunk during the battle of the Santa Cruz Islands).
Define Work what kind of work? US citizen can not serve British army but can do work in commercially
The main bombers used were the SB3C Helldiver, TBF/TBM Avenger, B-17 Flying Fortress, B-24 Liberator, B-25 Mitchell, B-29 Superfortress, and the B-26 Marauder.
Your basic Land, Sea, Air and Space defenses: US Army US Navy US Air Force US Marines
Tuskegee Airmen .
Expected flights of incoming US Army Air Corps B-17 Flying Fortress bombers "may" have led to some distraction(s).