New Philadelphia is a city in Tuscarawas County, Ohio, United States, 71 miles south of Cleveland on the Tuscarawas River. It was first incorporated in 1808. Coal and clay are found in the vicinity. In the past, mining interests and the manufacturing of steel, canned goods, roofing tile, sewer pipe, bricks, vacuum cleaners, stovepipes, carriages, flour, brooms, and pressed, stamped, and enameled goods occupied the people. In 1900, 6,213 people lived here; in 1910 8,542; in 1920, 10,718; and in 1940, 12,328 people lived here. The population was 17,056 at the 2000 census. It is the county seat of Tuscarawas County.