1. In 1862, the Dakota War of 1862 (also known as the Sioux Uprising) began in southwestern Minnesota. Many Dakota people were forced out of their land and onto reservations, causing tension to build up between the settlers and Native American communities. The conflict lasted for several weeks, resulting in the deaths of hundreds of Dakota people.

2. March 11, 1889, is the date when the Dakota Territory was split in half, creating the northern state of North Dakota and the southern state of South Dakota. This was done in order to increase the number of states in the U.S. and to aid in the mining industry in the area. The two states were admitted to the Union on November 2, 1889.

3. On March 11, 1897, the state of South Dakota passed a bill that allowed for women to vote and hold political office. This made South Dakota the first state in the U.S. to grant women suffrage by legislative action (Wyoming was the first state to give women the right to vote in 1869, but it was done by territorial legislation).

4. In 1937, the Missouri River flooded its banks and caused widespread damage in South Dakota and several other states. The flood is considered one of the worst natural disasters in U.S. history, and it led to the creation of the Pick-Sloan Plan in 1944, which aimed to develop and manage the Missouri River basin.

5. The Crazy Horse Memorial, located in the Black Hills of South Dakota, was started on March 11, 1948. The monument is still under construction and is being built to honor the Lakota warrior Crazy Horse, who fought against the U.S. government in the late 1800s. When completed, the monument is expected to be the largest in the world.