1. In 1804, the Lewis and Clark Expedition passed through what is now South Dakota on June 23. They arrived at the mouth of the Cheyenne River after traveling hundreds of miles up the Missouri River.

2. On June 23, 1874, a group of Lakota Sioux led by Chief Sitting Bull defeated Colonel George Armstrong Custer and his troops at the Battle of the Little Bighorn. The battle, also known as Custer's Last Stand, remains one of the most famous conflicts in American history.

3. In 1910, the first passenger train arrived in Rapid City, South Dakota, on June 23. The train brought new residents and visitors to the city and helped spark its growth as a regional hub.

4. On June 23, 1983, the state of South Dakota officially established its state song, "Hail, South Dakota!" The song was written by Deecort Hammitt and is still sung at official state functions today.

5. In 2002, the Crazy Horse Memorial, a massive carving of the Lakota warrior Crazy Horse on a horse, reached a major milestone on June 23 when workers completed the carving of the horse's head. The memorial, which is still under construction, is set to be the largest mountain carving in the world when completed.