People lived in this area that now is Arizona at least
20,000 years ago before written history. In the 1200s all of this civilization disappeared. This civilization probably disappeared  from a drought. Later on, Native American tribes such as Hopi, Zuni, Navajo, and Apache lived on the land. Today 22 tribes still live in Arizona. Spanish explores first arrived in the 1530s, continuing through the 1840s, Arizona, California, Utah, Nevada, and New Mexico were all a part of Mexico. Arizona became a state in 1912, February 14. The United States got this part of the land from winning the Mexican-American war in 1848.