The design was named in honor of Major General William "Billy" Mitchell, a pioneer of U.S. military aviation. Used by many Allied air forces, the B-25 served in every theater of World War II and after the war ended many remained in service, operating across four decades. Produced in numerous variants, nearly 10,000 Mitchells rolled from NAA factories. These included a few limited models, such as the United States Marine Corps' PBJ-1 patrol bomberand the United States Army Air Forces' F-10 reconnaissance aircraft and AT-24 trainers.
The majority of B-25s in American service were used in the war against Japan in Asia and the Pacific. The Mitchell fought from the Northern Pacific to the South Pacific and the Far East. These areas included the campaigns in the Aleutian Islands, Papua New Guinea, the Solomon Islands, New Britain, China, Burma and the island hopping campaign in the Central Pacific. The aircraft's potential as a ground-attack aircraft emerged during the Pacific war. The jungle environment reduced the usefulness of medium-level bombing, and made low-level attack the best tactic. Using similar mast height level tactics and skip bombing, the B-25 proved itself to be a capable anti-shipping weapon and sank many enemy sea vessels of various types. An ever-increasing number of forward firing guns made the B-25 a formidable strafing aircraft for island warfare. The strafer versions were the B-25C1/D1, the B-25J1 and with the NAA strafer nose, the J2 sub-series.