South Dakota Statehood
South Dakota entered the Union alongside North Dakota as part of the rapid western and plains admissions of the late nineteenth century.
How This State Entered The Union
Statehood is where constitutional structure meets regional history: the point where a place entered the Union as an equal state.
Admission To The Union
South Dakota became the fortieth state on November 2, 1889, admitted on the same day as North Dakota.
Path To Statehood
Its route moved through Dakota Territory, rail expansion, settlement, and growing agricultural and commercial infrastructure on the plains.
Why It Matters
South Dakota matters because it helps show how the federal system kept converting vast interior territory into equal states rather than leaving it indefinitely under territorial rule.
Read Next
Go back to the state page, then return to the larger constitutional story that made equal state membership possible.
Larger Context
Federalism and the founding era give the admission story its larger constitutional frame.