Towards the end of World War II, a tracked, fully enclosed armored personnel carrier was developed under the designation M44 (T16) that was based on the M18 Hellcat.

The M44 was extremely large (51,000 lb combat weight); carrying 24 infantry as well as a driver, bow gunner and vehicle commander.

It was evaluated at Fort Knox and Aberdeen Proving Ground after the end of the war, but, ultimately, the army rejected the M44 as being too large - at the time, their tactical doctrine required infantry squads of ten men.

On 26 September 1946, the development of the T18 armored utility vehicle was approved with International Harvester (IHC) contracted to produce four prototypes.

The prototypes were originally powered by a six-cylinder Continental AO-895-2 air-cooled gasoline engine, which exhausted through the hull side grills.

The M75 shared many chassis/suspension components with the M41 Walker Bulldog light tank, which was also powered by a Continental air-cooled engine.

The M75 has an almost identical layout to later U.S. armored personnel carriers: the driver sits in the front left of the hull, with the air-cooled six-cylinder horizontally opposed Continental AO-895-4 gasoline engine to his right.

[3] The engine developed a maximum of around 295 horsepower (220 kW) at 2660 rpm, giving the vehicle a top speed of 43 mph (69 km/h).