South Dakota South Dakota South Dakota () is a U.S. state in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux Native American tribes, who compose a large portion of the population and historically dominated the territory. South Dakota is the seventeenth largest by area, but the fifth smallest by population and the 5th least densely populated of the 50 United States. As the southern part of the former Dakota Territory, South Dakota became a state on November 2, 1889, simultaneously with North Dakota. Pierre is the state capital and Sioux Falls, with a population
South Dakota State Guard Guard was in federal service. Prior to the creation of the modern National Guard of the United States, the United States maintained a relatively small professional military and relied on state militias to augment the federal military in times of war. In 1901, the South Dakota Legislature designated the South Dakota State Guard as the organized militia of South Dakota, and required that the state maintain a certain minimum strength of cavalry, artillery, and infantry units. After the passage of the Militia Act of 1903, state militia units were reorganized into National Guard units and operated as a reserve component