Population (2020 Census): 886,667
Square Miles: 77,047
State Capitol: Pierre
The State of South Dakota is a part of the vast domain, which was acquired by the United States through the celebrated Louisiana Purchase in 1803. President Thomas Jefferson purchased the territory, which includes the present states of Missouri, Kansas, Nebraska, Iowa, Minnesota, North and South Dakota, Montana, and Idaho, from France for fifteen million dollars and the assumption of certain claims held by citizens of the United States against France.
Although nine states eventually were organized out of the Louisiana Purchase, during their existence as territories, the boundaries of these divisions were subject to frequent and marked changes, with names appearing and disappearing.
As part of what was called the Louisiana Territory in 1812, the part of South Dakota lying west of the Missouri River became known as the "Mandan Territory” and the area lying east of the Missouri River became incorporated into the Missouri Territory. The eastern half of the state was included in the Michigan Territory in 1834, and two years later it became part of the Wisconsin Territory. In 1849, after the organization of Wisconsin as a state, the area east of the Missouri River was included in the Minnesota Territory. The portion of South Dakota west of the Missouri River was included in the Nebraska Territory in 1854.
The admission of Minnesota as a state in 1885 left all the country west of its boundaries along the Big Sioux River to the Missouri River without any organization, legal name, or existence. This part was, by common consent, designated by the name of Dakota, a Native American name that means "confederated" or "leagued together," and was originally derived from the great associated tribe of Native Americans, known in their own language as Dakotas.
In 1861, President James Buchanan signed the Organic Act, creating the Dakota Territory, including the present states of North and South Dakota, Montana, Wyoming, and a small part of Nebraska. By 1868, the Dakota Territory consisted of only what are North and South Dakota today. In 1889, the "Omnibus Bill" or the Enabling Act was adopted, which provided for the dividing of Dakota Territory into the states of North and South Dakota. This enabled the two Dakotas, Montana, and Washington to formulate constitutions.
Today, South Dakota is located in the heartland of the United States. It is a rectangular area approximately 370 miles by 210 miles. Its 77,047 square miles make it the 16th largest in size among the fifty states. South Dakota has a population of around 886,667.
(The introductory material to the chronology was substantially derived from the “Introductory,” Revised Code of South Dakota, 1903, and the “Dakota Historical Sketch,” South Dakota Manual, 1905.)
(The total population estimate is from the Annual Estimates of the Population for Counties of South Dakota, based on July 2020 U.S. Census Data estimates.)