Arizona

Humans most likely lived in what is now Arizona more than 25,000 years ago. The Cochise culture arose in southeastern Arizona more than 10,000 years ago, followed by pueblo-building cultures including the Hohokam, Ancestral Pueblo, Mogollon, Sinagua, Salado, Cohonina and Patayan. The nomadic Apache and Navajo probably arrived in the region between AD 1100 and 1500.⁠[1][2]

Twenty-two Indigenous sovereign nations live in Arizona today. The Havasupai, Hualapai, Navajo and Hopi and several Paiute tribes live near the Grand Canyon and maintain ties to it.⁠[3][4]

Marcos de Niza explored the region in 1539, guided by Estéban. The 1540 expedition of Francisco Vázquez de Coronado found no gold; a scouting party from it led by García López de Cárdenas became the first Europeans to view the Grand Canyon. Coronado claimed the land for Spain in the 1540s.⁠[1][3]

In 1692 Father Eusebio Kino established the first of many missions, among them Tumacacori and San Xavier del Bac; he founded the San Xavier del Bac mission in 1700, and its church near Tucson is the oldest European structure in the state.⁠[1][5]

Tucson, the first important city to rise in the region, was established as a presidio in 1776. Because of Apache resistance, Spanish settlement was long limited to a few missions, presidios and ranches south of Tucson.⁠[1][6]

After Spanish rule ended, Mexico held the region until the Mexican-American War (1846–1848). In 1848, under the Treaty of Guadalupe Hidalgo, the United States acquired the part of present-day Arizona north of the Gila River, which was at first part of New Mexico Territory; fewer than 1,000 Hispanic people lived in Arizona at the time.⁠[1][5][6][7]

From 1851 Army Corps of Engineers expeditions searched for a wagon road route to California, and the government placed army posts at key sites to protect travelers and settlers.⁠[7]

On December 30, 1853, James Gadsden, the American minister to Mexico, signed a treaty acquiring a roughly 30,000-square-mile region of present-day southern Arizona and southwestern New Mexico, the land south of the Gila River. The U.S. Senate ratified the treaty with changes and President Franklin Pierce signed it; Mexico gave final approval on June 8, 1854.⁠[8][1]

Mining began at Ajo in 1854, and the PlanetPlanet LabsPlanet Labs (brand name Planet) is a San Francisco-based Earth observation satellite company founded in 2010 by three NASA scientists; it designs, builds and operates a constellation of imaging satellites and provides daily imagery data and analysis of Earth. The company is a public benefit corporation listed on the New York Stock Exchange under the ticker PL.Open the full entry mines on the Colorado River opened around the same time. Gold was discovered along the Gila River in 1857, and mining flourished there until the early 1860s. More profitable silver was found at Tombstone in 1877, a boom that ended in 1886 when the mines flooded, and the richest copper find came at Bisbee in 1877. By 1876 the Clifton-Morenci district had two large-scale operations.⁠[7][1]

Copper was Arizona’s leading industry until the 1950s, and the state still mines and processes about two-thirds of the copper produced in the United States; copper was important enough by 1888 that the flag design includes a copper-colored star.⁠[7][3]

During the Civil War, Confederate forces from TexasTexasTexas is a U.S. state in the south-central United States, with its capital at Austin and its largest city Houston. It was admitted to the Union on December 29, 1845, as the 28th state, and the 2020 census (April 1, 2020) counted 29,145,505 residents.Open the full entry nearly halted overland transportation in the region.⁠[1]

The Civil War and concern over railroad routes to California renewed efforts to create a new territory, and on February 24, 1863, President Abraham LincolnAbraham LincolnAbraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th president of the United States (1861–1865). Born to a frontier farming family in Kentucky, he had less than a year of formal schooling, taught himself law, and served in the Illinois legislature and the U.S. House of Representatives before winning the presidency as the Republican candidate in 1860. During the Civil War he preserved the Union, issued the Emancipation Proclamation in 1863 and pushed the Thirteenth Amendment abolishing slavery through Congress. He was shot by John Wilkes Booth at Ford’s Theatre in Washington on April 14, 1865, and died the next day.Open the full entry signed H.R. 357, creating the Territory of Arizona. The territorial government was formally organized on December 29, 1863, at Navajo Springs, and the first capital was Fort Whipple.⁠[9][1]

Between 1870 and 1891 the number of grazing cattle rose from 5,000 to more than 1.5 million, and range cattle were a major source of income from the 1860s until World War II. In the 1870s homesteaders, including Mormon immigrants from UtahUtahUtah is a U.S. state bordered by Idaho to the north, Wyoming to the northeast, Colorado to the east, Arizona to the south and Nevada to the west, with its capital at Salt Lake City. It was admitted to the Union on January 4, 1896, as the 45th state, and the 2020 census (April 1, 2020) counted 3,271,616 residents.Open the full entry, tried farming along the few streams, but droughts, floods and heavy capital needs showed that farming would have to be large-scale and organized.⁠[1][7]

The Camp Grant Massacre took place on April 30, 1871. The conflicts known as the Apache Wars continued until the Apache leader Geronimo surrendered in 1886. Cochise, the Chiricahua Apache chief who resisted the U.S. Army, died in 1874.⁠[1]

The Southern Pacific reached Yuma in 1878 and Tucson in 1880 on its line from New Orleans to Los Angeles, and in 1883 the Atchison, Topeka and Santa Fe was completed across northern Arizona, linking St. Louis with California.⁠[1][7]

Phoenix was made the territorial capital in 1889 and the state capital in 1912. The territorial statehouse was dedicated in 1901.⁠[1][3]

The Hamilton Joint Statehood Bill of 1906 proposed admitting Arizona and New Mexico as a single state, but Arizonans rejected it in a referendum in November 1906.⁠[3]

On June 20, 1910, Congress passed an act (61st Congress, 2nd Session, Chapter 310) enabling the New Mexico and Arizona territories to form constitutions and state governments; it provided for an Arizona constitutional convention of 52 delegates and required each constitution to be ratified by voters before being submitted to Congress. The convention met that year, and the constitution was adopted in 1911.⁠[1][3][10][11]

Roosevelt Dam, the largest dam of the Salt River Project, was completed in 1911, when the project began delivering water to farmers in the Phoenix area.⁠[1][7]

On August 15, 1911, President William H. Taft vetoed H.J. Res. 14, which would have admitted New Mexico and Arizona, objecting mainly that Arizona’s constitution allowed the recall of judges, which he said went against the need for an independent judiciary. S.J. Res. 57, dated August 16, made Arizona’s admission conditional on voters adopting an amendment removing the judicial recall provision, and Taft approved it on August 21. Voters then removed the provision.⁠[12][13][3]

President Taft signed the statehood bill on February 14, 1912, making Arizona the last of the 48 contiguous states to be admitted; New Mexico had become the 47th state on January 6, 1912. The first three justices of the state Supreme Court, Alfred Franklin, Donald L. Cunningham and Henry D. Ross, began service the same day. The first U.S. senators, Henry Fountain Ashurst and Marcus A. Smith, took office on March 27, 1912. The judicial recall clause was later restored.⁠[3][14][15][16][1]

After statehood Arizona promoted itself as the place of the “five Cs”: copper, cattle, cotton, citrus and climate. Its dry air drew health seekers, and the 1920s brought motor courts, dude ranches and resorts for tourists, winter residents and retirees.⁠[7]

In 1918 Arthur P. Davis proposed a very tall dam in Boulder Canyon on the Arizona–NevadaNevadaNevada is a state in the western United States bordered by Oregon, Idaho, Utah, Arizona, and California; its capital is Carson City. It was admitted to the Union on October 31, 1864, as the 36th state, and its population in the 2020 census (April 1, 2020) was 3,104,614.Open the full entry border. On November 24, 1922, representatives of the seven Colorado River Basin states signed the Colorado River Compact in Santa Fe, New Mexico. President Calvin Coolidge signed the Boulder Canyon Project Act on December 21, 1928, and the Black Canyon site was selected that year. Construction began in 1931: Six Companies received the contract on March 11 and notice to proceed on April 20. The first concrete was placed on June 6, 1933; President Franklin D. Roosevelt dedicated the dam on September 30, 1935; and generator N-2 began full operation on October 26, 1936. In 1947 the 80th Congress designated the project’s key structure “Hoover Dam” in honor of President Herbert Hoover.⁠[17]

The Grand Canyon was first protected as a forest preserve in 1893, designated a game reserve in 1906 and declared a national monument by President Theodore Roosevelt under the Antiquities Act in 1908; in 1919 President Woodrow Wilson signed the act of Congress making it a national park. In 1975 President Gerald Ford signed a law doubling the park’s size and setting its current boundary.⁠[4]

As war loomed in 1940, the federal government opened military bases in Arizona, especially for training pilots; the climate and distance from the coasts made the state a site for flight schools and other bases.⁠[1][7]

After President Franklin D. Roosevelt signed Executive Order 9066 on February 19, 1942, more than 120,000 Japanese Americans, two-thirds of them U.S.-born citizens, were incarcerated; Gila River and Poston in Arizona were two of the ten “War Relocation Centers.”⁠[18]

In September 1942 Phillip Johnston proposed using the Navajo language for secure communication, and the Marine Corps began with an initial 30 Navajo recruits; the number rose to 420 members of the tribe who served as code talkers during the war. Fewer than 28 people outside the Navajo tribe could understand the language. Code talkers transmitted classified messages in campaigns including Guadalcanal, Bougainville, Guam, Peleliu and Okinawa.⁠[19]

After the war, migration from other states, especially the Midwest, made Phoenix one of the fastest-growing urban areas in the country, and refrigeration and air conditioning were especially important in making the state livable. By the 1980s Arizona had become one of the leading high-technology states.⁠[7][1]

In 1963, after a long dispute with California, the U.S. Supreme Court upheld Arizona’s right to 2.8 million acre-feet of Colorado River water a year plus the entire flow of the Gila River.⁠[7]

In 1968 Congress authorized the Central Arizona Project to carry Colorado River water to the Phoenix and Tucson areas; the project was completed in 1993.⁠[7]

The U.S. Census Bureau delivered the 2020 Census apportionment results to the President on April 26, 2021, when the resident population of the 50 states and the District of Columbia totaled 331,449,281. Arizona was apportioned 9 seats in the U.S. House of Representatives, the same as after the 2010 Census, and has 11 electoral votes in the 2024 and 2028 presidential elections.⁠[20][21][22][23]

The Arizona State Legislature consists of a Senate of 30 members and a House of Representatives of 60 members; each of the 30 legislative districts elects one senator and two representatives. The Second Regular Session of the Fifty-seventh Legislature (2026) adjourned sine die on June 13, 2026.⁠[24][5]

The governor is the chief executive, and the Secretary of State is next in line of succession. As of November 2026 the governor is Katie HobbsKatie HobbsKatie Hobbs is an American Democratic politician and social worker who has been governor of Arizona since 2023. She previously served as Arizona secretary of state and as minority leader of the Arizona Senate, and was re-elected governor in November 2026.Open the full entry, Arizona’s 24th governor, sworn in on January 2, 2023. She began her career as a social worker, was elected to the Arizona House in 2010, served four terms in the legislature, including two as Senate Minority Leader, and was elected the state’s 21st Secretary of State in 2018.⁠[5][25][26]

The state Supreme Court has seven justices, appointed by the governor and subject to retention votes for regular six-year terms; the chief justice is chosen by the other justices for a five-year term, and Chief Justice Ann A. Scott Timmer took that office on July 1, 2024. Andrew Gould and John R. Lopez IV were both appointed on January 6, 2017, as a result of a bill expanding the court. The state has 15 counties.⁠[27][15][1]

Arizona is the sixth largest U.S. state by area, bordered by California and Nevada to the west, Utah to the north, New Mexico to the east and Mexico to the south. In Census Bureau 2010 measurements, the state has a total area of 113,990 square miles (295,234 km²), of which 113,594 square miles (294,207 km²) is land and 396 square miles (1,026 km²) is water.⁠[28][29]

The highest point is Humphreys Peak near Flagstaff, at 12,633 feet (3,851 m); the lowest, in the southwest corner, is about 100 feet (30 m) above sea level. The Colorado River forms the western border, and other major rivers include the Little Colorado, the Bill Williams and the Gila.⁠[1]

The Grand Canyon, in the north of the state, began to be carved through Paleozoic rock by the Colorado River 5 to 6 million years ago; it is 277 river miles long, 18 miles wide and nearly a mile deep, and draws about 4.5 million visitors a year.⁠[4]

Summer highs above 100 °F (38 °C) are common in the southwest. The record low is –40 °F at Hawley Lake on January 7, 1971, and the record high 128 °F at Lake Havasu City on June 29, 1994. Average annual precipitation ranges from about 3 inches (8 cm) at Yuma in the southwest to 18 inches (46 cm) at Flagstaff.⁠[1][5]

The Census Bureau estimated the population at 7,623,818 on July 1, 2025 (Vintage 2025), up 67,394 (0.9%) from 7,556,424 on July 1, 2024, the 7th largest numeric gain and the 8th highest growth rate among the states.⁠[30]

In the 2020 Census nearly one-third of residents identified as Hispanic, most of Mexican heritage; more than 6 percent identified as wholly or partly Native American; African Americans and Asian Americans each made up about 4 percent; and non-Hispanic whites more than half. More than three-fifths of the people live in Maricopa County, where Phoenix is located.⁠[1]

The Navajo reservation covers 23,400 square miles, nearly three-fifths of it in Arizona, and about 100,000 Navajo live in the state. In the early 21st century Arizona’s population grew at almost three times the national rate.⁠[6]

Preliminary data released by the U.S. Bureau of Economic Analysis on March 28, 2025, put Arizona’s 2024 current-dollar GDP at $552,167 million, with real GDP growth of 2.7%.⁠[31]

Service industries employ more workers and generate more income than any other sector. Before World War II the economy centered on mining, lumber, cattle and crops; from the late 1940s manufacturing and services grew, producing computers and electronics, aircraft, spacecraft, chemicals and machinery. The Copper Mountain district at Morenci in Greenlee County is a leading copper-mining area.⁠[1]

Cotton is a leading crop and lettuce output is high; other crops include citrus, broccoli, cauliflower, pecans, hay and wheat. Tourism is a major industry, drawing visitors to parks, monuments and dude ranches.⁠[1]

The first public school opened in Tucson in 1871; in 1879 the territorial legislature created the office of superintendent of public instruction, and organization of the public school system began in 1883. The main public universities are the University of Arizona in Tucson, Arizona State University in Tempe and Northern Arizona University in Flagstaff. Lowell Observatory in Flagstaff was established in 1894.⁠[1]

Frank Lloyd Wright began Taliesin West north of Scottsdale in 1937. The Heard Museum in Phoenix presents American Indian arts and cultures; La Posada in Winslow, on Route 66, is a railroad hotel designed by Mary Elizabeth Jane Colter; the Center for Creative Photography is on the University of Arizona campus; and Arcosanti, along I-17, is an experimental town exploring “arcology.”⁠[5]

The name likely comes from an O’odham phrase meaning “place of small spring.” The state’s nickname is the “Grand Canyon State.”⁠[3][32]

The design of the state seal is set by Article 22, § 20 of the state constitution: a sun rising between mountain peaks, a storage reservoir and dam, irrigated fields and orchards, grazing cattle, and a quartz mill with a miner holding a pick and shovel, encircled by the words “Great Seal of the State of Arizona” and the statehood year 1912. The motto “Ditat Deus,” Latin for “God Enriches,” appears above the drawing.⁠[33]

The state flag is set by statute: the lower half is a blue field and the upper half is divided into 13 rays, six light yellow and seven red, starting at the center, with a copper-colored five-pointed star in the middle; the flag “represents the copper star of Arizona rising from a blue field in the face of a setting sun.” The governor’s office describes the 13 rays as standing for the original 13 colonies and the western setting sun, the red and yellow as the colors of the Spanish flag carried by Coronado, and the copper star as marking Arizona as the largest copper-producing state. The state colors are blue and old gold.⁠[34][32]

The state flag became official in February 1917. It was designed by Colonel Charles Harris, captain of the state rifle team, and grew out of a temporary banner he drew up for the 1910 National Rifle Matches; Governor Thomas Campbell presented the flag to the public that September.⁠[35]

The state flower is the saguaro cactus blossom (1931), the tree the palo verde (1954), the gemstone turquoise (1974), the neckwear the bola tie (1973), the bird the cactus wren, the fossil petrified wood (1988), the reptile the Arizona ridge-nosed rattlesnake (1986), the mammal the ringtail (1986), the fish the Apache trout (1986), the amphibian the Arizona tree frog (1986) and the butterfly the two-tailed swallowtail (2001). The state song is the “Arizona March Song,” written in 1915, and “Arizona” by Rex Allen, Jr., was adopted as an alternate state song in 1982.⁠[32]

State of Arizona: Official website: https://az.gov/ (opens in a new window).⁠[36]

Office of the Arizona Governor: Official website: https://azgovernor.gov/ (opens in a new window).⁠[25]

Arizona State Legislature: Official website: https://www.azleg.gov/ (opens in a new window).⁠[24]

Arizona Judicial Branch: Official website: https://www.azcourts.gov/ (opens in a new window).⁠[27]