
Watertown is a city in New York and the county seat of Jefferson County. It was named for the many falls on the Back River, and it was settled in 1800 by pioneers from New Hampshire. It developed in the early 19th century as a manufacturing center, and its industrial wealth led to it having more millionaires per capita than any other city in the nation by the early 20th century. It was also the birthplace of the five and dime store and the safety pin. In 2016, Watertown had a population of 25,900 people.