The following is a timeline of the history of the city of Phoenix, Arizona, United States.
Prior to 19th century
1–300 – Hohokam establish several villages along the Gila River. 300 – Ceramics appear in the Hohokam culture. 450 – Pueblo Grande settled (approximate date). 600–1300 – Hohokam build large network or irrigation canals throughout the area. 1300 – Hohokam have largest population in the southwest. 1300–1450 – Periods of drought alternate with flooding (approximate date). 1450 – Pueblo Grande abandoned due to drought (approximate date).
19th century
1848 – With the end of the Mexican–American War, the area which includes today's Phoenix becomes part of the United States, as part of the New Mexico Territory. 1863 – Nearby Wickenburg becomes the first town to be established in what is now Maricopa County, Arizona. 1865 – Camp McDowell (later Fort McDowell) is set up on the Verde River. 1867 November: Jack Swilling, resident of Wickenburg, establishes the Swilling Irrigating and Canal Company with the intent to develop the Phoenix area, which he became impressed with after viewing the area on a visit to Camp McDowell. December: Swilling leads a group of 17 miners from Wickenburg to the Phoenix area and begins the process of developing a canal system. 1868 May 4: Phoenix is officially recognized by the Board of Supervisors of Yavapai County, which at that point contained Phoenix. June 15: First post office established, in the Swilling homestead, with Swilling as postmaster. Swilling has completed almost 3 miles of his canals. Mary Adeline Gray, the first European woman settler, and her husband Columbus, arrive. They brought with them their African-American domestic servant Mary Green, who would become the Territory's first black settler. Salt River floods for the first of many times during Phoenix's settlement. 1870 October 20: Town site selected in what is currently downtown Phoenix. Town laid out, original town site consists of 320 acres, or 0.5 square miles. Population of the Salt River Valley reaches 240, the Arizona Territory has 9,658 people. 1700 acres under cultivation in the Salt River Valley. Maricopa Canal completed. 1871 February 12: Maricopa County is broken out of Yavapai County, Phoenix becomes the county seat. July 4: First wheat ground in Valley at Birchard's Mill. First permanent building, the Hancock residence, is constructed at Washington and First Streets. The second building, a brewery, is constructed. The first store (Hancock's) and the first church (Central Methodist) open in Phoenix. The Tempe Irrigating Canal Co. is created. Tempe founded by Charles T. Hayden. Population of Phoenix reaches 500. 1872 Adobe schoolhouse constructed. September 5: Public school in session. Phoenix's first wedding, between George Buck and Matilda Murray. Phoenix's first Chinese settlers arrive. The first bookstore and newsstand opened by Edward Irvine. 1873 – Hellings Mill expands to include a hog-slaughterhouse. 1874 School built on Center Street. Hayden's mill opens. It will remain in operation for more than 100 years. Phoenix's formal patent for the town site is formally granted. Salt River floods. 1875 – Salt River floods. 1877 – Maricopa Library Association organized. 1878 Salt River Herald, the valley's first newspaper, begins publication. The first bank, a branch of the Bank of Arizona, opens. Population reaches 1500. Brick factory opens. Grand Canal completed. Mesa is founded. 1879 Presbyterian church established. Salt River Indian Reservation is formed. The Southern Pacific railroad reaches Maricopa. 1880 Arizona Gazette newspaper begins publication. Methodist church established. Population: 1,800. First legal hanging in Maricopa County. 1881 February 25: Phoenix officially incorporated when Governor John C. Frémont signs "The Phoenix Charter Bill", instituting a mayor-council form of government. La Guardia, the valley's first Spanish language newspaper, begins publication. May 3: John T. Alsap defeated James D. Monihon, 127 to 107, to become the city's first mayor. May 9: City Council begins meeting. June 24: Catholic church dedicated. Phoenix Rangers organized in response to hostile Apache activity in Tonto Basin. 1883 Cotton cultivation is brought to the valley. Two smallpox outbreaks. City creates the position of Health Officer. Mesa City incorporates.
1884 Arizona Industrial Exposition begins. Valley Bank founded by William Christy. The Women's Christian Temperance Union opens a Phoenix branch. Phoenix Light & Fuel (electricity and heat) is established 1885 Arizona Canal completed. Phoenix broken up into four wards, although city officials remain citywide offices. Destructive fire destroys major portions of the town. Arizona Insane Asylum is awarded to Phoenix. 1886 A second major fire destroys several buildings and results in approximately $100,000 in damage. Phoenix Fire Department established, when bond issue passes establishing 2 fire companies. First private gas lighting company established. First telephone company opens. Phoenix Opera House is completed. Arizona Insane asylum's construction is completed. 1887 Maricopa-Phoenix railway and horse-drawn Street Railway begin operating. Public water system created. Public Health Department is established. Mule-drawn streetcar system established. Salt River Valley News begins weekly publication. 1888 Electric power company created. New city hall opens. November 4 – Phoenix Chamber of Commerce established. Peoria is founded. 1889 Capital of Arizona Territory relocated to Phoenix from Prescott. Citrus cultivation is begun in the valley by the Arizona Improvement Company. 1890 Arizona Republican newspaper begins publication. Population: 3,152. Walnut Grove dam bursts north of the city, 50 people killed. Ladies Benevolent Society formed. 1891 Phoenix Indian School opens. Largest flood in valley history occurs. Telephones come to Phoenix. A territorial convention is held in Phoenix. The idea of becoming a state is discussed, but is voted down. 1892 The Phoenix Sewer and Drainage Department is created. The Phoenix Indian School holds its first classes. 1893 The Phoenix Street Railway switches over from mule-drawn to electrical streetcars. The Arizona Territory passes a law allowing cities, including Phoenix, to annex land surrounding the city, as long as it obtained the permission of the inhabitants of that area. 1894 Orangedale (later called Scottsdale) is founded by Winfield Scott. The city passes an ordinance limiting prostitution to a single block area. The city's speed limit is raised to 6 mph. Tempe incorporates. 1895 Santa Fe, Prescott and Phoenix Railway begins operating. Arizona Gazette newspaper begins publication. Phoenix Union High School opens, and the Phoenix Union High School district is created. Rosson House built in downtown Phoenix. Sisters of Mercy Hospital (today called St. Joseph's Hospital and Medical Center) opens. The New York Store is opened by Sam Korrick; Nathan and Isaac Diamond open the Boston Store; and Baron Goldwater opens a branch of his Flagstaff store, M. Goldwater and Brothers. 1896 The Adams Hotel opens. Date Palms are introduced into the valley. 1897 The Friday Club begins a movement to open a public library. 1898 El Demócrata newspaper begins publication. The block of the red-light district is now illegal. Doris Opera House Opens. First public library opens. 1899 – Phoenix Library Association created. 1900 Dorris Theatre opens (approximate date). City accesses unincorporated lands, area increases from .5 acre to over 2 acres. In spite of efforts by the Women's Temperance Union, Phoenix has 28 saloons and 18 casinos. First automobiles arrive in the city. Population: 5,544.
20th century
1900s 1901 February 25: The State Capitol building is dedicated, built at a cost of $130,000. Drought hits the city. The Phoenix Women's Club is founded. 1903 February 7: Salt River Project founded (as the Salt River Valley Water Users' Association). Voters approve a bond to create a municipal waterworks. 1905 The largest agricultural crop is alfalfa. Flooding once again causes issues in the city. 1906 Construction begins on the Theodore Roosevelt Dam. Gambling is outlawed in the city. 1907 St. Luke's Home, a tuberculosis treatment center, opens. The YMCA raises $100,000 to construct a building in town. 1908 Salt River again floods. Granite Reef dam completed. Carnegie Library is completed and open to the public. 1909 – The Central Avenue bridge over the Salt River is approved.
1910s 1910 Speed limit is increased to 12 mph in city limits; city has 329 licensed cars. City schools establish an official segregation policy. The Adams Hotel is destroyed by fire, but is rebuilt. Guidelines concerning surface water rights are established by the Kent decree. Population reaches 11,134. 1911 May 18: Roosevelt Dam dedicated by Theodore Roosevelt, it is the first multi-purpose (electricity and water) dam built under the National Reclamation Act. Center Street Bridge opens. 1912 February 14: Arizona becomes the 48th state of the United States; Phoenix becomes the state capital. Women are granted the right to vote. Chandler is founded by Alexander Chandler. 1913 City adopts council-manager form of government (previously mayor-council), becoming one of the first cities in the country to adopt this form of government. 35% of the votes cast were by women. City has 646 registered automobiles. Ash Avenue Bridge is completed. 1914 Arizona votes to ban alcohol. William Fairish becomes the city's first manager. 1915 St. Mary's Basilica dedicated. The city's first sewer treatment plant is completed. 1917 Arizona adopts its state flag. Litchfield is founded when the Goodyear Tire Company purchases a tract of land. Salt River Valley Water Users Association gains control of the Salt River Project. Migrant workers from Mexico are brought in to pick cotton. 1918 Alfalfa falls to the number two agricultural product, behind cotton. The Rialto Theatre opens. Spanish flu infects a significant portion of the population. 1919 – In anticipation of the upcoming U.S. Census, the city votes to extend the city limits.
1920s 1920 Congregation Beth Israel formed. The Heard Building, the first skyscraper in Phoenix, is constructed. Phoenix Union High School has 2000 students. The entirety of the original Phoenix town site is now completely paved. A precipitous drop in the price of cotton, from $1.35 to $0.35 a pound, creates a financial crisis in the valley. Phoenix has over 11,000 registered vehicles. Chandler is incorporated. Population reaches 29,053. 1921 Temple Beth Israel, the valley's first synagogue, opens. "Rich, Resolute, Ready, Phoenix, Salt River Valley" becomes the official tourism slogan of Phoenix. 1922 Valley and Gila River Banks merge. Water from the Verde River becomes available through a wooden pipeline. KFAD becomes the city's first radio station (later renamed KTAR; it was followed shortly by KFCB, which today is called KOY). 1923 Cave Creek Dam is completed. Salt River Project absorbs the Tempe Irrigating Canal Company. Union Station built. Deaconess Hospital (today known as Banner Good Samaritan Medical Center) opens. 1924 Luhrs Building constructed. The depression caused by the drop in the cotton price in 1920 ends. Phoenix Sanitarium opens. Jokake Inn opens. South Mountain Park (originally named Phoenix Mountain Park) is created. 1925 12 subdivisions are annexed by Phoenix. Phoenix Fine Arts Association formed. The private electric streetcar system is purchased by the City of Phoenix for $20,000. Mormon Flat Dam completed. Voters approve a separate high school for blacks. First municipal airport is opened, near Christy Road and 59th Avenue.