1. On December 3, 1929, Arizona officially became a state. Arizona was the last of the 48 contiguous states to be admitted to the Union.
2. In 1811, Spanish explorer Jose Cortez was the first known European to travel through the area now known as Arizona on December 3. He traveled through the Santa Cruz River Valley near present-day Nogales.
3. On December 3, 1863, the first newspaper in the territory of Arizona was published in Tucson. The newspaper was called the Weekly Arizonian and was published by Sylvester Mowry.
4. In 1873, one of the most infamous events in Arizona history occurred on December 3. This was the date of the infamous Camp Grant Massacre, where a group of Apache Indians were massacred by a group of white settlers and Mexican troops.
5. On December 3, 1992, the Superstition Wilderness Area was officially designated as a wilderness area by the United States Congress. The area covers 160,200 acres of public land east of Phoenix and includes the famous Superstition Mountains.