Father Kino was the next European in the region. A member of the Society of Jesus (“Jesuits”), he led the development of a chain of missions in the region. He converted many of the Indians to Christianity in the Pimería Alta, now southern Arizona and northern Sonora, in the 1690s and early 18th century. Spain founded presidios (“fortified towns”) at Tubac in 1752 and Tucson in 1775.
Mexican Administration:
When Mexico achieved its independence from the Kingdom of Spain and its Spanish Empire in 1821, what is now Arizona became part of its Territory of Nueva California, (“New California”), also known as Alta California (“Upper California”). Descendants of ethnic Spanish and mestizo settlers from the colonial years still lived in the area at the time of the arrival of later European-American migrants from the United States.
Mexican- American War:
During the Mexican–American War (1847–1848), the U.S. Army occupied the national capital of Mexico City and pursued its claim to much of northern Mexico, including what later became Arizona Territory in 1863 and later the State of Arizona in 1912. The Treaty of Guadalupe Hidalgo (1848) specified that, in addition to language and cultural rights of the existing inhabitants of former Mexican citizens being considered as inviolable, the sum of US$15 million dollars in compensation (equivalent to $424,269,230.77 in 2017) be paid to the Republic of Mexico. In 1853, the U.S. acquired the land south below the Gila River from Mexico in the Gadsden Purchase along the southern border area as encompassing the best future southern route for a transcontinental railway.
Civil War:
What is now known as the state of Arizona was initially administered by the United States government as part of the Territory of New Mexico until the southern part of that region seceded from the Union to form the Territory of Arizona. This newly established territory was formally organized by the Confederate States government on Saturday, January 18, 1862, when President Jefferson Davis approved and signed An Act to Organize the Territory of Arizona, marking the first official use of the name “Territory of Arizona”. The Southern territory supplied the Confederate government with men, horses, and equipment. Formed in 1862, Arizona scout companies served with the Confederate States Army during the Civil War. Arizona has the westernmost military engagement on record during the Civil War with the Battle of Picacho Pass.
The Federal government declared a new U.S. Arizona Territory, consisting of the western half of earlier New Mexico Territory, in Washington, D.C., on February 24, 1863. These new boundaries would later form the basis of the state. The first territorial capital, Prescott, was founded in 1864 following a gold rush to central Arizona.
Although names including “Gadsonia,” “Pimeria,” “Montezuma” and “Arizuma” had been considered for the territory, when 16th President Abraham Lincoln signed the final bill, it read “Arizona,” and that name was adopted. Montezuma was not derived from the Aztec emperor, but was the sacred name of a divine hero to the Pima people of the Gila River Valley. It was probably considered—and rejected—for its sentimental value before Congress settled on the name “Arizona.”
Late 19th Century:
Brigham Young, patriarchal leader of The Church of Jesus Christ of Latter-day Saints in Salt Lake City in Utah, sent Mormons to Arizona in the mid- to late 19th century. They founded Mesa, Snowflake, Heber, Safford, and other towns. They also settled in the Phoenix Valley, Tempe, Prescott, and other areas. The Mormons settled what became northern Arizona and northern New Mexico. At the time these areas were located in a part of the former New Mexico Territory.
20th Century to Present:
During the Mexican Revolution from 1910 to 1920, several battles were fought in the Mexican towns just across the border from Arizona settlements. Throughout the revolution, numerous Arizonans enlisted in one of the several armies fighting in Mexico. Only two significant engagements took place on U.S. soil between U.S. and Mexican forces: Pancho Villa’s 1916 Columbus Raid in New Mexico, and the Battle of Ambos Nogales in 1918 in Arizona. The Americans won the latter.