Dover was founded by two brothers-in-law who took a horseback trip from Baltimore, Maryland, in 1802 and liked the fertile plateau they found at the confluence of the Tuscarawas River and Sugarcreek. They were Jesse Slingluff and Christian Deardorff who found the site where they later started Dover, which was owned by Col. James Morrison of Kentucky, who had received it from the federal government for Revolutionary War services. They returned in 1805 and in 1806 purchased 2,175 acres for $4,622. Dover was laid out in 1807 and Deardorff and Slingluff families were prominent citizens of the town through its growth from a grist mill at a Tuscarawas River ford to a thriving industrial city. The town's first prosperity was stimulated by the construction of the Ohio and Erie canal in the late 1820's. Warehouses were built and flour mills constructed. The only toll collecting office in the county was situated in Dover.

Local industries included a woolen mill, blast furnaces, saw mills and tanneries. The City was always called Dover but the post office was called Canal Dover for many years because of other Dover, Ohio, post offices that were later abolished, after which the Canal Dover Post Office became Dover. This change was made December 18, 1915. The town was incorporated in 1842 and Joseph Slingluff was its first Mayor. The charter was permitted to lapse after a few years and it was not restored until 1867. The importance of the canal began to decline in the 1880's under the impact of the railroads. The Tuscarawas branch of the Cleveland and Pittsburgh and the Marietta and Wheeling, now a part of the Baltimore & Ohio, were built. Steel mills were constructed and clay manufacturing was developed, which, with other diversified industries attracted a cosmopolitan population.

Dover today is a prosperous and progressive Ohio city with a almost perfect balance of industrial, commercial and agricultural activity. The 18 industrial plants of the city have employed an average of more than 2,500 workers over a five year period. Dover has been conspicuous for the dependability and skill of its workers, and its industrial plants boast a low turnover of employees, who because of diversity of manufacture in the area are skilled in all modern industrial techniques. From Tuscarawas County come most of the raw materials that go into the manufactured products of Dover. Included are coal, clay, limestone, shale, molding, sand, petroleum, natural gas and rock sale. Among the products of Dover industrial plants are brick and allied clay products, electric appliances, manufactured screw products, tanks, boilers, steel fabrication, drawn tungsten wire, cold rolled strip and stainless steel, a wide range of chemical products, plastic moldings, wire, stone, steel sheets, roofing, stove and furnace pipe, buckets, tubs, wood stoves, castings - both ferrous and non ferrous. The City has municipal light plant and water systems, maintains a park, stadium, modern public and parochial high schools, four new public grade schools and a parochial grade school, a new YMCA, Legion Memorial Hall, a park system and has 14 churches and a Salvation Army Building. The Tuscarawas County Fairgrounds and Union Hospital are located in the City. Points of tourist interest includes Dover Dam, key dam of the Muskingum Watershed Conservancy District, and the Warther Museum and the J. E. Reeves Home and Museum.