USAAC/USAAF/USAF Bomber Aircraft
There were four series of USAAC/USAAF/USAF bomber aircraft. The original series began in 1920 and ended in 1924:
First Series of USAAC bombers
The second series began in 1924 and ended in 1930:
Second Series of USAAC Bombers
The third series began in 1930 and ended in 1962:
Third Series of USAAC/USAAF/USAF Bombers
The fourth series began in 1962 and continues to the present day:
Fourth Series of USAF Bombers
