The suburban growth of America in the Fifties helped create a huge market for riding lawn mowers. The nation's largest farm machinery manufactures saw a need to get involved in this new market. After John Deere and International Harvester introduced their own riding mower product lines, Allis-Chalmers needed to catch up to the trend to. To meet this challenge, they partnered the Simplicity Manufacturing company and in 1961 roller out the premiere Allis-Chalmers garden tractor. It was called the B-1 and featured a 7.25 horsepower engine. The B-1 was developed from Simplicity's 725 Model with changes to the paint scheme, decals, and sheet metal construction. The B-10 was released shortly after and it featured a full 9 horses. The Big-10 was next and had a 10 horsepower engine. The Big-10 was later switched back to the B-10 after the introduction of the even more powerful B-12. All Allis-Chalmers garden tractors were painted yellow and featured Briggs engines until 1971.By 1965 Allis-Chalmers decided to outright purchase Simplicity, but they faced government challenges due to concerns about fair trade laws. To ensure legal compliance, Allis-Chalmers built a brand new Lexington South Carolina plant in 1967 which was specifically designed to manufacture garden tractors. This plant began producing the B-207, B-110, B-112, HB-112, B-208, B-210, B-212, and HB-212.
The 206, 207, and 208 made Up the Homesteader series which was in production between 1972 and 1974. In 1972 Allis Chalmers also introduced the model 616 which was developed from the Simplicity PowrMax but featured orange paint and a redesigned hood. In 1973 the 616 became the 620 and boasted a powerful 20 HP engine. The 620 became the 720 in 1975 and the only difference was an upgraded front axle. A second 616 model was released layer which was simply a Simplicity model 4216 with new paint and was unrelated to the PowrMax 616 model.