1. On September 28, 1961, the Grand Canyon National Park added 10,972 acres of land to its boundaries, increasing the size of the park by nearly 50%. This land was acquired from the Kaibab National Forest and included parts of the Marble Canyon and the Buckskin Plateau.

2. In 1910, the famous western novelist Zane Grey arrived in Payson, Arizona, for a hunting trip. Grey fell in love with the area and eventually built a cabin there that he used as a writing retreat. The cabin still stands today and is now a museum dedicated to Grey's life and work.

3. On September 28, 1986, the Arizona Cardinals (then known as the Phoenix Cardinals) played their first regular-season game in Arizona after moving from St. Louis. They defeated the Seattle Seahawks 16-10 in front of a crowd of over 64,000 fans at Sun Devil Stadium in Tempe.

4. In 1927, the University of Arizona welcomed its first African American student, Roy Irwin. Irwin faced racial discrimination during his time at the university, but he persisted and went on to become a successful civil engineer.

5. September 28, 1866, marks the founding of Prescott, Arizona, by a group of prospectors who discovered gold in the area. Prescott was named after William H. Prescott, an American historian and author who focused on the Spanish conquest of America. Today, Prescott is known for its historic downtown area and its many festivals and events.