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.
Simplicity also continued manufacturing tractors in Port Washington with alternate paint and decal schemes, but similar designs. The 300 series was the first Simplicity to feature orange body paint and cream colored hoods. The 300 series tractors were powered by Kohler engines. 1973 saw the introduction of the 400 series which were drastically different form the Simplicity Port Washington produced models. The deck and attachments had changed greatly. The B-207 and B-208 got new paint schemes in 1971 but retained Briggs engines.
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.
With the repeal of the Fair Trade Laws, the Lexington factory closed down and all production was moved to Port Washington. Now most Simplicity and Allis-Chalmers garden tractors were identical aside from the paint and decal labeling. A few Allis Chalmers models were unique to the AC brand though. The 700 series in 1974 featured a new orange paint scheme which mirrored the look of larger AC farm machinery. The 700 series featured mostly Kohler engines, but some 716 had Briggs instead. The 600 series was released simultaneous to the 700 series and was meant to replace the Homesteader lin. In 1976 the 800 series was introduced. All 600 and 800 series tractor models featured only Briggs engines. The 900 series came in 1979 and featured Kohler engines only, with the exception of a few 916's which featured Briggs engines. Allis-Chalmers garden tractors continued to be manufactured until 1984 when AC was bought by the Deutz Corp and relabeled as Deutz-Allis. Models after that point were painted lime green.