The 75 mm pack howitzer was designed in the United States in 1920s to meet a need for an artillery piece that could be moved across difficult terrain. In August 1927, the weapon was standardized as Howitzer, Pack, 75mm M1 on Carriage M1 but by 1940 only 91 pieces were made. In September 1940 however, a year into World War II, the howitzer was put into mass production and the earlier M1 was succeeded by the slightly modified M1A1 with pneumatic steel rimmed wheels. Production continued until December 1944. Our model has optional pneumatic and steel rimmed wheels where the latter were retained for use in jungles of the Far East. The only significant changes during the mass production period were carriage improvements. The original carriage M1 was of box trail type, with wooden wheels. Requirement for a lightweight howitzer for airborne troops led to introduction of the M8 carriage, similar except new wheels with pneumatic tires.