History
Shortly after the beginning of World War II, it became apparent to US Army planners that there was a dire need for an armored, self-propelled artillery vehicle to support the troops involved in armored operations. Until something more viable could be developed, the army used the M3 half-track with an M2 105mm howitzer mounted in the crew compartment. This vehicle was designated as the T-19. However, this quickly proved inadequate and needed to be replaced, preferably by a fully tracked, armored vehicle able to offer better crew protection. Using the chassis from an M3 medium tank, two pilot models designated T32 were built and tested. Upon successful completion of the tests, the T32 was accepted for service in February 1942 as the M7 HMC (Howitzer Motor Carriage) with production starting in April 1942. The main armament was the M2 105mm howitzer, along with the M2 .50 cal. machine gun for AA and personal defense.