1. On April 21, 1870, the first train arrived in Cheyenne, Wyoming, marking the completion of the Union Pacific Railroad. This opened up transportation opportunities for trade and travel in the state.
2. In 1926, Wyoming celebrated its first Arbor Day on April 21. This holiday encourages the planting of trees and is still recognized annually in the state.
3. On April 21, 1983, the Wyoming State Capitol building was added to the National Register of Historic Places. The building, which opened in 1890, has been the site of many important political events in the state's history.
4. In 2015, April 21 was declared "John Colter Day" in Wyoming. Colter was a famous mountain man who explored much of the region in the late 1700s and early 1800s.
5. April 21, 2019 marked the 150th anniversary of women's suffrage in Wyoming. In 1869, the territorial legislature passed a bill giving women the right to vote and hold office, making Wyoming the first state to grant suffrage to women.