It is also the principal city of the Watertown Micropolitan Statistical Area, which includes all of Codington County.

Watertown was founded in 1879 as a rail terminus when the Chicago & Northwestern Railroad reactivated part of a line it had constructed to Lake Kampeska.

[1] During the 1880s, Watertown prospered as a transportation hub after the railroads had extended farther west.

Along with several other cities, it had been a candidate for capital of the new state of South Dakota,[1] losing to the more centrally located Pierre.

The city's newspaper, the Watertown Public Opinion, began publishing in 1887.

[12] The route included a slight bend to bring it closer to Watertown.

Although it is a humid city, it is relatively dry for its climatic category, due to its position in the Great Plains, which still provides an even greater thermal amplitude, especially in the higher values.

33.0% of all households were made up of individuals, and 12.4% had someone living alone who was 65 years of age or older.

30.5% of all households were made up of individuals, and 11.8% had someone living alone who was 65 years of age or older.

There is also a satellite campus of Mount Marty College,[18] a private Catholic school based in Yankton, South Dakota.

The Aspen Institute awarded the prize in March 2017 in Washington, D.C., after an intense data collection process that included a rigorous review of critical elements of student success, such as learning, completion, and employment after college.

The community's "Prairie Lakes Wellness Center" opened in 2017, adjacent to the middle school.

Jefferson Lines provides intercity bus service to Watertown.

[20] According to the city's 2018 Comprehensive Annual Financial Report,[23][24] Watertown's largest employers are: