The Diamond T Motor Car Company was founded by Charles Arthur Tilt in Chicago in 1905. The company produced cars, but in 1911 the first small truck was produced. This model proved successful, and within a few years car-production was abandoned altogether. During the Great War Diamond was supplier of the Class B “Liberty” trucks to the US Army.
In the early 1930´s the company supplied a number of 1 and 1½ ton trucks to the US Army, but mostly the production was concentrated on the medium to heavy end of the market.
By spring 1942 production was turned over to war production, and the period 1940 to 1945 around 50.000 vehicles was produced.
A new range was launched in 1947 and by 1951 lighter trucks had been dropped. From then on production was concentrated on heavy-duty trucks, both normal and forward control.
The Diamond T company was absorbed by White in 1958, and production was moved to the Reo plant in Michigan in 1961.
The trucks were re-named Diamond-Reo in 1967 and the company was sold to F.L. Coppaert in 1971. Diamond Reo Trucks Inc., as the company was called, fell into financial problems in 1975 and the company was bought by Osterlund Inc. in Hansbury, Pennsylvania.
.
.