During the Great Depression, the Fate-Root-Heath Company, later called the Plymouth Locomotive Works designed and built the famous "Silver King" (originally the "Plymouth") tractor, a favorite of local farmers and known for its fast road gear. The tractors were produced until the 1954 when it was sold to Mountain State Engineering in West Virginia and then discontinued, and parts returned to Plymouth, OH. After the discontinuation of the Silver King Tractor, the many records, design plans, and many other important information was destroyed near by. Not much remains of primary sources documents, the few that were saved were done by factory employees who knew what this information could be used and needed in the future. From surviving records tractors where shipped to OH, IN, KY, PA, NY, NJ, NH and many other New England & Midwest states. About 200 Plymouth tractors, around 8,500 Silver King tractors were built in several models, styles, and sizes, and 75 Silver Kings were produced by the Mountain State Engineering Company.