Watertown is a city in the state of New York and the county seat of Jefferson County. It is situated approximately 20 miles south of the Thousand Islands. As of the 2010 census, it had a population of 27,023, an increase of 1.2% since 2000. The U.S. Army post Fort Drum is near the city.Named after the many falls located on the Black River, the city developed early in the 19th century as a manufacturing center. From years of generating industrial wealth, in the early 20th century the city was said to have more millionaires per capita than any other city in the nation.Geographically, Watertown is located in the central part of Jefferson County. It lies 72 miles northeast of Syracuse and 31 miles south of the Ontario border. The city is served by Watertown International Airport.The city claims to be the birthplace of the five and dime store and the safety pin, and is the home of Little Trees air fresheners. It manufactured the first portable steam engine.