Arizona Statehood Day in the United States Date in the current year: February 14, 2024

Arizona is one of the two states that form the core of the American Southwest, the other one being New Mexico. It is also one of the Mountain States, alongside Colorado, Idaho, Montana, Nevada, New Mexico, Utah and Wyoming. Arizona was one of the last US territories to become a state; after its admission, Alaska and Hawaii were the only remaining territories of the United States.

For thousands of years before the arrival of the first Europeans, the territory of present-day Arizona was inhabited by numerous indigenous tribes. Native American cultures that flourished throughout the region included the Hohokam culture, the Mogollon culture, and the Ancestral Puebloans.

The first European to set fut in Arizona and make contact with the natives was Marcos de Niza, an Italian-born missionary and Franciscan friar, in 1539. In 1540–1542, the region was explored by Francisco Vázquez de Coronado’s expedition. After that, Spanish settlers started to migrate to Arizona. In the late 17th and early 18th centuries, Jesuit missionary Father Eusebio Kino developed a chain of missions and converted the locals to Christianity.

Following Mexico’s independence from Spain in 1821, Arizona became part of the Mexican territory of Alta California (“Upper California”), also known as Nueva California (“New California). It remained Mexican until Mexico’s defeat in the Mexican-American War of 1846–1848.

After the war, more than half of Mexican territory was ceded to the United States according to the Treaty of Guadalupe Hidalgo. The ceded lands included most of what is now Arizona. In 1853, the United States acquired more land from Mexico in the so-called Gadsden Purchase. The purchase included present-day southern Arizona.

The entirety of present-day Arizona was originally administered as part of the Territory of New Mexico. However, in 1858, members of the New Mexico territorial legislature voted in favor of the creation of the Arizona Territory, bordering New Mexico along the 109th meridian. However, the Congress wasn’t in a hurry to approve this decision.

The Territory of Arizona split from New Mexico during the American Civil War. It joined the Confederate States and was formally organized on January 18, 1862. The United States occupied Arizona on July 8, 1863. The Federal Government officially approved the formation of the Territory of Arizona on February 24, 1863. For most of the war, Arizona was controlled by the California Column troops, while its Confederate government was in exile in San Antonio.

Arizona officially became the 48th state of the United States on February 14, 1912. It was the last of the contiguous states to be admitted to the Union. Although Arizona Statehood Day isn’t a public holiday in the state of Arizona and government offices remain open, the anniversary of Arizona’s admission to the Union is marked with events and programs that focus on the history and culture of Arizona.