1. 1803: The Louisiana Purchase, in which the United States purchased the vast territory of Louisiana from France, included present-day South Dakota.
2. 1861-1865: South Dakota was part of the Dakota Territory during the American Civil War, and many of its residents fought on both sides of the conflict.
3. 1889: South Dakota became the 40th state of the United States.
4. 1890: The Wounded Knee Massacre, in which hundreds of Lakota Sioux were killed by US troops, took place in South Dakota.
5. 1930s: The Great Depression hit South Dakota hard, causing widespread poverty and unemployment.
6. 1941-1945: South Dakotans served in the military during World War II, and the state played a role in the production of war materials.
7. 1960s: The civil rights movement had a significant impact on South Dakota, leading to the desegregation of public facilities and the passage of laws prohibiting discrimination.
8. 1970s: The development of the Black Hills gold mine led to a boom in the state's economy.
9. 1980s: The farm crisis of the 1980s caused severe economic hardship for South Dakota's farmers and ranchers.
10. 1990s: The state's economy began to recover in the 1990s, and South Dakota became a popular tourist destination.
11. 2000-present: South Dakota has continued to grow and prosper in the 21st century, and has become known for its beautiful natural scenery, its strong agricultural sector, and its friendly people.