De Smet, SD

De Smet is Kingsbury County's seat in South Dakota's East River country. The town was platted in 1880 when the railroad arrived and incorporated in 1883; the first train came during that founding era. It was named for Belgian Jesuit missionary Pierre-Jean De Smet, and the 2020 census counted 1,056 residents. Glacial lakes and prairie surround the town, including Lake Thompson, while the county courthouse and business blocks give it a county-seat role.

The Ingalls family arrived with the railroad construction crews, and De Smet later became the setting for several Laura Ingalls Wilder books. The Laura Ingalls Wilder Memorial Society preserves the family homes and school history, while the annual pageant and covered-wagon tours keep that connection on the local calendar. De Smet also carries a practical present-day map of schools, health care, agriculture, and small businesses. The courthouse, schools, and storefronts still make it a working town as well as a literary destination. It is a prairie county seat where railroad history, glacial water, and a much-read family story still share the same streets.