The Diamond T Motor Car Company was founded in Chicago in 1905 by C. A. Tilt. Reportedly, the company name was created when Tilt’s shoe-making father fashioned a logo featuring a big “T” (for Tilt) framed by a diamond, which signified high quality. The company’s hood emblem on trucks was a sled dog in harness. From its beginnings manufacturing touring cars, the company later became known for its trucks. By 1967, as a subsidiary of White Motor Company, it was merged with Reo Motor Company to become Diamond Reo Trucks, Inc.
During World War II, Diamond T produced a classic heavy truck in the 980/981, a prime mover which was quickly acquired by the British Purchasing Commission for duty as a tank transporter tractor. Coupled with a Rogers trailer, the truck gave sterling service with the British Army in North Africa Campaign, where its power and rugged construction allowed the rescue of damaged tanks in the most demanding of conditions. In addition Diamond T built the entire range of the G509 series 4 ton 6X6s, including cargo, dump, semi tractor, and wrecker trucks, as well as some lighter trucks, and even G7102 half tracks. Diamond T ranked 47th among United States corporations in the value of World War II military production contracts. Diamond T manufactured three pickup trucks: The Model 80,201 and the Model 202. The pickups were powered by the Hercules QX-series 6-cylinder engines. The model 80 was produced from 1936 to 1938 and the Model 201 was produced from 1938 to 1949.