Allis-ChalmersClassic Machines: The Allis-Chalmers HD-19 tractorContrafed PUblishingMarch 29, 2016August 16, 2022 by Contrafed PUblishingMarch 29, 2016August 16, 2022 Allis-Chalmers was the first heavy machinery builder to enter the big track-type tractor development race immediately following World War II. Richard Campbell looks at its...