1. On April 9, 1864, the first post office was established in the town of Tucson, Arizona. It was originally called Tucson Station and was located on the Overland Mail route.

2. In 1940, the first American troops arrived in Arizona for World War II training. Over the next four years, more than 300,000 men and women would train in 185 camps across the state.

3. On April 9, 1959, the Grand Canyon National Park expanded by over 10,000 acres with the addition of the Marble Canyon National Monument. This area is now known as the Marble Canyon Wilderness Area.

4. In 1994, the Phoenix Suns set a new NBA record for most three-pointers in a season with 712. Led by players like Dan Majerle and Danny Ainge, the Suns made it to the NBA Finals that year.

5. On April 9, 2019, Arizona became the first state in the country to recognize occupational licenses from other states for military spouses. This law made it easier for military families to move from state to state without having to re-apply for occupational licenses.