<P> The first successful American tractor was built by Charles W. Hart and Charles H. Parr . They developed a two - cylinder gasoline engine and set up their business in Charles City, Iowa . In 1903, the firm built 15 "tractors", a term with Latin roots coined by Hart and Parr, and a combination of the words traction and power . Their 14,000 - pound #3 is the oldest surviving internal combustion engine tractor in the United States, and is on display at the Smithsonian National Museum of American History in Washington, D.C. The two - cylinder engine has a unique hit - and - miss firing cycle that produced 30 horsepower at the belt and 18 at the drawbar . </P> <P> In 1908, the Saunderson Tractor and Implement Co. of Bedford introduced a four - wheel design, and went on to become the largest tractor manufacturer in Britain at the time . While the earlier, heavier tractors were initially very successful, it became increasingly apparent at this time that the weight of a large supporting frame was less - efficient than lighter designs . Henry Ford introduced a light - weight, mass - produced design which largely displaced the heavier designs . Some companies halfheartedly followed suit with mediocre designs, as if to disprove the concept, but they were largely unsuccessful in that endeavor . </P> <P> While unpopular at first, these gasoline - powered machines began to catch on in the 1910s, when they became smaller and more affordable . Henry Ford introduced the Fordson, a wildly popular mass - produced tractor, in 1917 . They were built in the U.S., Ireland, England and Russia, and by 1923, Fordson had 77% of the U.S. market . The Fordson dispensed with a frame, using the strength of the engine block to hold the machine together . By the 1920s, tractors with gasoline - powered internal combustion engines had become the norm . </P> <P> Harry Ferguson applied for a British patent for his three - point hitch in 1926, a three - point attachment of the implement to the tractor and the simplest and the only statically determinate way of joining two bodies in engineering . The Ferguson - Brown Company produced the Model A Ferguson - Brown tractor with a Ferguson - designed hydraulic hitch . In 1938 Ferguson entered into a collaboration with Henry Ford to produce the Ford - Ferguson 9N tractor . The three - point hitch soon became the favorite hitch attachment system among farmers around the world . This tractor model also included a rear Power Take Off (PTO) shaft that could be used to power three point hitch mounted implements such as sickle - bar mowers . This PTO location set the standard for future tractor developments . </P>

When were tractors first manufactured on a large scale