An American WW2 Half Track trundles towards the main arena
The half-track design had been evaluated by the US Ordnance department using Citroën-Kégresse vehicles. The White Motor Company produced a prototype half track using their own chassis and the body of the M3 Scout Car.
In 1938, the White Motor Company took the Timken rear bogie assembly from a T9 half-track truck and added it to an M3 Scout Car, creating the T7 Half-Track Car. This vehicle was woefully underpowered, and when a further requirement came down from US Army artillery units for a prime mover (artillery tractor), a vehicle with an uprated engine was devised, then designated the T14. By 1940, the vehicle had been standardized as the M2 Half-Track car, and was being supplied to army units as both a prime mover and a reconnaissance vehicle. The latter was to serve in the interim, until more specialized vehicles could be fielded.
Between 1942 and 1943, these vehicles, just as with the M3 half tracks, would receive a number of modifications to the drive train, engine, and stowage, among other things.
Total production of M2 and derivatives was about 13,500 units. Later, to meet the needs of the Lend-Lease program, the International Harvester Company was brought in to manufacture vehicles similar to the M2, as the M9 adding another 3,500 units.