Fate-Root-Heath was formed in 1919 when Fate joined with Root-Heath in Plymouth, Ohio. A variety of machines were manufactured, but locomotives were the primary business. Seeking to diversify their line, the company designed a small tractor named the Plymouth. A fight with Chrysler over the Plymouth brand ended with the name being sold to the auto company and the Silver King name being introduced for the tractors. Sales were steady and successful, if small in comparison to the major tractor manufacturers. Fate-Root-Heath management sold the tractor division in 1954. The company changed its name to Plymouth Locomotive Works and was purchased by Ohio Locomotive Crane in 1999.
Ohio Locomotive Crane - official site
Silver King Tractors - site devoted to Silver King collectors