1. In 1901, the first passenger train arrived in Pierre, the capital city of South Dakota. This was a significant moment in the history of South Dakota as it helped boost the transportation industry in the state, making it easier and more convenient for people to move around.

2. On April 24, 1967, the Deadwood Centennial Commission was formed to commemorate the 100th anniversary of the founding of the town of Deadwood. Deadwood is known for its rich history and its association with famous figures such as Wild Bill Hickok and Calamity Jane.

3. In 1986, April 24 was declared Arbor Day in South Dakota. This day is set aside to encourage people to plant and care for trees. South Dakota is one of the few states that celebrates Arbor Day on this date, as it is usually celebrated on the last Friday in April.

4. On April 24, 1880, the first telegraph line was completed between Rapid City and Deadwood. This was a significant moment in the history of South Dakota as it enabled people to communicate more effectively over long distances, helping to boost business and social connections across the state.

5. In 2009, the South Dakota Historical Society Press released its book "South Dakota Leaders: From Pierre Chouteau, Jr., to Oscar Howe," celebrating some of the most notable people from South Dakota history. This book is a testament to the diverse and rich history of the state, highlighting the many individuals who have shaped it over time.