Watertown, city, seat of Jefferson County, northern New York, on the Black River, near Lake Ontario; incorporated as a city 1869. The river falls about 34 m (about 112 ft) here, providing power for industry; manufactures include railroad equipment, paper, electrical motors, ski lifts, medical supplies, and processed food. The city also serves as a gateway to the Thousand Islands and Adirondack Mountains resort areas. A community college is in Watertown, and Fort Drum, a large military reservation, is nearby. The Oneida people ceded the site of the city to New York State in 1788-89, and the community was founded in 1800. Population 27,861 (1980); 29,429 (1990); 20,237 (2000).
