1. In 1860, the first Pony Express riders arrived in Idaho, bringing news from the East Coast in record time. The Pony Express was a mail delivery service that used horseback riders to travel quickly across the United States, and Idaho was one of the stops on its route.

2. In 1890, Idaho became the 43rd state in the United States. This followed years of debates and negotiations between Idaho's residents and the federal government, and it gave the state full membership and representation in the U.S. Congress.

3. In 1928, the city of Boise experienced a devastating flood that killed several people and caused millions of dollars in damage. The flood was caused by heavy rain and snowmelt, and it swept through the city's streets and homes, leaving destruction in its wake.

4. In 1946, Idaho celebrated its centennial year, marking 100 years since its founding as a territory. The year was marked by parades, celebrations, and reenactments of important events in Idaho's history.

5. In 1968, Idaho Senator Frank Church announced his candidacy for president of the United States. Church was a popular politician in Idaho and had served in the U.S. Senate since 1957. However, he ultimately lost the Democratic nomination to Hubert Humphrey.