The United States acquired almost all of the area of South Dakota from France in 1803 as part of the Louisiana Purchase. A small portion in the northeast part of the present-day state was added by a convention signed with Great Britain in 1818. Dakota Territory was organized on March 2, 1861, from unorganized area formerly within Minnesota Territory and part of Nebraska Territory. Dakota Territory included all of the present-day states of North Dakota and South Dakota, most of Montana, the northern half of Wyoming, and a small part of Nebraska. The territory was reduced in 1863 with the organization of Idaho Territory, enlarged in 1864 with the addition of most of the remainder of present-day Wyoming, and again reduced with the organization of Wyoming Territory in 1868. In 1882, the state of Nebraska acquired an area north of the Keya Paha River and Niobrara River. South Dakota was admitted to the Union simultaneously with North Dakota on November 2, 1889, as the 39^th and 40^th states, with generally the same boundary as the present state.

Census data for the combined area in present-day North Dakota and South Dakota are available in the 1860 census (and listed in national tables with South Dakota). The 1860 census population is for territory reported as unorganized Dakota and territory now in Montana. Although the state had not yet been legally established, the 1870 and 1880 populations are for the area of the present state. The population of Dakota Territory as legally established was 135,177 in 1880 and 14,181 in 1870.

Data for the legally established state of South Dakota are available beginning with the 1890 census.

AMERICAN INDIAN AREAS

South Dakota has 11 American Indian areas. There are nine reservations, four with associated off-reservation trust lands.  There are also two off-reservation trust lands associated with reservations in neighboring states.

METROPOLITAN AND MICROPOLITAN STATISTICAL AREAS AND RELATED STATISTICAL AREAS

South Dakota has three metropolitan statistical areas, nine micropolitan statistical areas, and one combined statistical area.

COUNTIES

There are 66 counties in South Dakota.  Each county is governed by a board of commissioners.

COUNTY SUBDIVISIONS

There are 1,339 county subdivisions in South Dakota known as minor civil divisions (MCDs). There are 914 townships with functioning, but not necessarily active, governments.  Townships are each governed by a board of supervisors.  The 311 incorporated places in South Dakota are independent of MCDs and serve as 320 county subdivisions.  In addition, there are 105 unorganized territories in South Dakota.  Bennett, Bon Homme, Buffalo, Campbell, Custer, Dewey, Haakon, Harding, Potter, Shannon, Stanley, Sully, Todd, Walworth, and Ziebach Counties have no townships and are covered entirely by unorganized territories and incorporated places.

PLACES

South Dakota has 390 places; 311 incorporated places and 79 census designated places (CDPs).  The incorporated places consist of 156 cities, 154 towns, and 1 village.  Incorporated places are independent of county subdivisions.

CENSUS TRACT/BLOCK GROUPS/BLOCKS

South Dakota has 222 census tracts, 654 block groups, and 88,360 census blocks.

CONGRESSIONAL DISTRICTS

For the 111^th Congress (January 2009-January 2011), South Dakota had one congressional district.  For the 113^th Congress (January 2013-January 2015), South Dakota continues to have one congressional district as a result of reapportionment based on the 2010 Census.

SCHOOL DISTRICTS

South Dakota has 156 unified school districts.

STATE LEGISLATIVE DISTRICTS

There are 35 state senate districts and 37 state house districts in South Dakota.

URBAN AREAS

South Dakota has 28 urban areas; 3 urbanized areas and 25 urban clusters.

ZIP CODE TABULATION AREAS

There are 387 ZIP Code tabulation areas (ZCTAs) in South Dakota.

¹  Source:  U.S. Department of Commerce, Bureau of the Census, Fourteenth Census of the United States, 1923
²  Source:  U.S. Census Bureau, recomputation for historical county level data which relied upon aggregate county level population data with an estimated county centroid resulting in a possible error of up to one mile.
³  Source:  U.S. Department of Commerce, Bureau of the Census, Centers of Population for States and Counties, 1974
⁴  Source:  U.S. Census Bureau, Geography Division, recomputation from archived national block group/enumeration area data resulting in a possible error of up to 1,000 feet.
⁵  Source:  U.S. Census Bureau, Geography Division, recomputation from archived national block group data resulting in a possible error of up to 1,000 feet.
⁶  Source:  U.S. Census Bureau, computation from national block-level data