South Dakota History
South Dakota became a state in 1882.
Before that, however, we had people exploring SD, as early as 1743. From https://www.nps.gov/nr/travel/pierre_fortpierre/verendrye_site_pierre.html:
"The Verendrye Site, on Verendrye Hill overlooking the city of Fort Pierre just northwest of where the Bad and Missouri Rivers come together, is one of only a few verifiable sites associated with the first Europeans to explore the northern Great Plains region. Frenchman Pierre Gaultier De La Verendrye and his sons explored the interior of North America in the 18th century. In 1742, Francois and Louis-Joseph Verendrye embarked on an expedition to find a water route to the Pacific Ocean. Though the Verendryes’ epic achievements were dismissed as a failure in their time because they found no Northwest Passage to the Pacific, this site documents their undisputed role in the French effort to achieve colonial dominance in North America.
The Verendryes penetrated further into the heartland of North America than any previously known European explorers. They reached the area in South Dakota where Pierre and Fort Pierre are now located 61 years before Meriwether Lewis and William Clark first arrived in the area. At the end of March, 1743, after visiting with local Arikaras, they buried a lead plate at the site to lay the basis for French sovereignty on the upper Missouri, seeking to establish French control of the entire Mississippi River drainage."
Below is the Verendrye Plate, discovered by some school children playing on the hill in 1913.
Additional references:
