The B came in several different variations including the Asparagus B, Potato Special, and the IB industrial tractor, and gave rise to the larger Allis-Chalmers Model C. The Model B was styled by Brooks Stevens, an industrial designer and graphic designer.

In the early 1930s, Allis-Chalmers tractor division manager Harry Merritt's study of farm census figures showed that-they have a lot of potential in the field and even in the yard, of the nearly seven million farms in America, some four million were of 100 acres (0.40 km2) or less.

Furthermore, the million or so tractors used on American farms were generally unsuitably large for such acreage.

Although the Fordson tractor and then the first-generation row-crop tractors, including the Farmall, Allis-Chalmers's own Model WC, and others, had been gaining significant market penetration and making mechanised agriculture ever more popular, Merritt concluded that there was a need for four million small, inexpensive tractors to fill the needs of the small farmers still using horses.

[1][2][5] A total of 120,783 Model Bs were built at Allis-Chalmers factories in West Allis, Wisconsin and in Southampton, England.