The little town of Plymouth appears as no more than a dot on the map of Ohio, but has played a big part in America's agricultural history. In the late 1800's, Pennsylvania brickyard worker J.D. Fate and his business partner were attracted to this little town in north central Ohio by the community's promise to help them found an industry that would bring jobs to the area. The Fate and Gunsaullus Co. began building clay extruding machinery for making bricks in 1882. In 1892 Fate bought out his partner and formed the J.D. Fate Company, still making clay machinery.
In 1909 Fate organized the Plymouth truck company, building motor trucks under the trade name "Plymouth". The organization wasn't a great success and the Plymouth Truck Company went out of business in 1915, after building fewer than 200 trucks and a single car.
Part of the failure of the Plymouth truck and car business may have been the success of another of J.D. Fates enterprises. About the same time the trucks were being built, a clay machinery customer asked Fate if he could build a machine that would replace the mules then being used to move rail cars around the railroad yard at his plant. Fate's yard locomotive proved to be very successful, and laid the foundation for what would become the company's primary product, Plymouth Locomotives.
In 1919 Fate joined with Root-Heath Manufacturing Company and formed Fate-Root-Heath. The new organization continued to build clay machinery, yard locomotives, and added a line of sharpening equipment for reel type grass mowers. Business was good, and the company prospered until the economic crash of 1929.
By the early 1930's orders for expensive locomotives had slowed to a trickle. In order to keep the factory doors open, Fate-Root-Heath needed a product that was cheap enough that people could afford to buy in quantity. The town of Plymouth was located in the middle of prime Ohio farm land; a farm tractor would be a natural addition to the product line. A tractor was well within the company's engineering and production capabilities. Charles Heath, general manager of the company at that time, presented the idea of building a farm tractor to get the company through the depression. An employee recalls, "Charlie was the Kingpin of the operation. When Charlie hollered, everyone jumped, from the president on down. " So Fate-Root-Heath set out to build a farm tractor.
The first tractors were designed by the company's locomotive engineers, and looked it. Floyd Carter, chief engineer of the locomotive department, designed a huge, heavy affair powered by a big, slow speed Climax engine. This was just the kind of tractor farmers were turning away from in favor of lighter, more maneuverable machines. What was needed was a small, lightweight, inexpensive tractor.
All of the various models of Silver King tractors used the same serial number listings.
| Year | Serial Number |
| 1934 | 0 |
| 1935 | 326 |
| 1936 | 1001 |
| 1937 | 1986 |
| 1938 | 3025 |
| 1939 | 3876 |
| 1940 | 4245 |
| 1941 | 4906 |
| 1942 | 5256 |
| 1943 | 5594 |
| 1944 | 5710 |
| 1945 | 6161 |
| 1946 | 6449 |
| 1947 | 6947 |
| 1948 | 7475 |
| 1949 | 8245 |
| 1950 | 8395 |
| 1951 | 8545 |
| 1952 | 8627 |
| 1953 | 8708 |
| 1954 | 8717 |