Belle Fourche is a city in and the county seat of Butte County, South Dakota, United States. Its population was 5,617 at the 2020 census. It is near the geographic center of the United States, which moved some 550 miles northwest from the geographic center of the contiguous United States in Lebanon, Kansas with the admission of Alaska and Hawaii in the mid-20th century.

Francis Everett Townsend was an American physician and political activist in California. In 1933, he devised an old-age pension scheme to help alleviate the Great Depression. Known as the "Townsend Plan", this proposal would pay every person over age 60 $200 per month, with the requirement it all be spent quickly. It was never enacted but the popularity of the Plan influenced Congress to start the Social Security system, which involved much smaller amounts. The Plan was organized by real estate salesman Robert Clements, who made Townsend only a figurehead while the Plan expanded to thousands of clubs in many states. Townsend was born just outside Fairbury, Illinois, where he is memorialized by a post office named in his honor.