1. In 1846, the famous Mormon Battalion camped at the junction of the Gila and Colorado rivers on December 28, while on their way to California during the Mexican-American War. This was a significant event in Arizona history, as the group became the first non-native people to cross through the state's southern region.

2. On December 28, 1864, Confederate soldiers under the command of General James H. Carleton attacked and killed over 100 friendly Apache Indians near Camp Grant, located in what is now present-day Tucson. The event is known as the Camp Grant Massacre, and it remains one of the darkest moments in Arizona's history.

3. The San Francisco Peaks, which are located in northern Arizona near Flagstaff, received their name on December 28, 1629. This was the feast day of San Francisco de Asis, and the peaks were named in his honor by a group of Spanish explorers who visited the area during that time.

4. On December 28, 1912, Arizona's Statehood Convention approved the state's constitution, which paved the way for Arizona to become the 48th state in the United States on February 14, 1912. This was a significant moment in Arizona's history, as the state finally gained full recognition as an official state in the country.

5. In 1985, the Arizona Cardinals football team played their final game in St. Louis before moving to Arizona and becoming the Arizona Cardinals a year later in 1986. The team's move to Arizona marked the beginning of professional football in the state and has since become a beloved part of Arizona's sports culture.