Henry Ford had grown up on a farm, and had taken a personal interest in providing an affordable tractor to the small farmer. He built his first experimental tractor in 1907 and was said to have made more than 50 different prototypes until the development of the Fordson F in 1917. The Fordson name was selected for two reasons. There was already a Ford Tractor Company in Minneapolis at the time, and the Ford Motor Company shareholders did not approve of tractor production. So Henry established an entirely new firm, Ford & Son Inc., which was shortened to Fordson.
Ford stopped tractor production in the US in 1928, choosing to focus on the Model A car that was replacing the Model T. Fordson production, however, continued in England. The Ford name was brought to tractors in the US in 1939. For a time, there were two separate divisions, Fordson in England, and Ford in the USA. In 1964, the two branches were merged and the Fordson name was dropped.
Oscar's Fordson Page - Detailed information on Fordson tractors