The M19 was developed from the T65 which was based on the M5 light tank chassis. With the M5 going out of production, the project adopted the M24 Chaffee Light tank chassis and was designated the T65E1. It was accepted into service in May 1944 as the M19 MGMC, equipping several U.S. Army anti-aircraft units during World War II. The M19A1 was an improved variant with an auxiliary engine and spare barrels for the 40 mm Bofors guns.
