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Basic Information

2010 Census Population: 6,392,017 (16th)
Land Area: 113,594.1 square miles (6th)
Density: 56.3 persons per square mile (33th)
Capital: Phoenix
Became a State: February 14, 1912 (48th)
Bordering States: California, Colorado, Nevada, New Mexico, Utah
International Border: Mexico
Abbreviation: AZ
ANSI Code: 04


The United States acquired most of the area of Arizona from Mexico in 1848. The United States acquired additional area, comprising the southern part of Arizona, from Mexico in 1853 as part of the Gadsden Purchase. Arizona Territory was organized from the western part of New Mexico Territory on February 24, 1863. Part of Arizona Territory north and west of the Colorado River was added to the state of Nevada in 1866, resulting in generally the same boundary as the present state of Arizona.

Although the territory had not yet been legally established, census data are available for Arizona beginning with the 1860 census. For an explanation of the revision to the 1860 population of Arizona, see Richard L. Forstall, Population of States and Counties of the United States: 1790-1990, Washington, DC: U.S. Government Printing Office, 1996, page 14.

Data for the legally established state of Arizona are available beginning with the 1920 census.

About the Geographic Areas


Arizona has 21 federally recognized American Indian reservations; 4 with associated off-reservation trust lands in the state.


Arizona has six metropolitan statistical areas and five micropolitan statistical areas.


There are 15 counties in Arizona.  Each county is governed by a board of supervisors.


There are 80 county subdivisions in Arizona.  They are all census county divisions (CCDs), which are delineated for statistical purposes, have no legal function, and are not governmental units.  CCDs were first established in Arizona for the 1960 census.  Prior to 1960, the minor civil divisions used in the census include supervisorial districts, election precincts, justice precincts, school districts, land-survey townships, and Indian reservations.


Arizona has 451 places; 90 incorporated places and 361 census designated places (CDPs).  The incorporated places consist of 45 cities and 45 towns.  The minimum population threshold required for incorporation is 1,500. 


Arizona has 1,526 tracts, 4,178 block groups, and 241,666 blocks.


For the 111th Congress (January 2009-January 2011), Arizona had eight congressional districts.  For the 113th Congress (January 2013-January 2015), Arizona has nine congressional districts as a result of reapportionment based on the 2010 Census.


Arizona has 104 elementary school districts, 15 secondary school districts, and 99 unified school districts.


There are 30 state senate districts and 30 state house districts in Arizona.


Arizona has 69 urban areas; 9 urbanized areas and 60 urban clusters.


There are 408 ZIP Code tabulation areas (ZCTAs) in Arizona.

Centers of Population

Year North Latitude West Longitude
20106 33° 22′ 06″ 111° 51′ 52″
20006 33° 22′ 25″ 111° 49′ 43″
19905 33° 21′ 08″ 111° 46′ 13″
19804 33° 19′ 29″ 111° 43′ 06″
19703 33° 17′ 09″ 111° 41′ 15″
19603 33° 15′ 41″ 111° 30′ 19″
19503 33° 22′ 11″ 111° 31′ 55″
19402 33° 20′ 24″ 111° 49′ 26″
19302 33° 18′ 40″ 111° 44′ 02″
19201 33° 21′ 03″ 111° 12′ 55″
19101 33° 24′ 18″ 110° 59′ 38″
19001 33° 34′ 20″ 111° 15′ 58″
18901 33° 15′ 51″ 111° 25′ 39″
18801 33° 17′ 36″ 111° 25′ 32″

1  Source:  U.S. Department of Commerce, Bureau of the Census, Fourteenth Census of the United States, 1923
2  Source:  U.S. Census Bureau, recomputation for historical county level data which relied upon aggregate county level population data with an estimated county centroid resulting in a possible error of up to one mile.
3  Source:  U.S. Department of Commerce, Bureau of the Census, Centers of Population for States and Counties, 1974
4  Source:  U.S. Census Bureau, Geography Division, recomputation from archived national block group/enumeration area data resulting in a possible error of up to 1,000 feet.
5  Source:  U.S. Census Bureau, Geography Division, recomputation from archived national block group data resulting in a possible error of up to 1,000 feet.
6  Source:  U.S. Census Bureau, computation from national block-level data

Most Populous, Largest, and Dense Areas

Population Land Area
(square miles)
Population Density
(Persons per square mile)

Name Population Name Area Name Density
County Maricopa County 3,817,117 Coconino County 18,618.89 Maricopa County 414.9

 - Inc Place Phoenix city 1,445,632 Phoenix city 516.70 Guadalupe town 6,833.0
 - CDP San Tan Valley CDP 81,321 Valle CDP 243.89 Donovan Estates CDP 12,430.8

List of Entities

See the Gazetteer Files for a list of geographic entities. See the Metropolitan and Micropolitan Statistical Areas page for a list of metropolitan and micropolitan statistical areas and related statistical areas.

Page Last Revised - October 8, 2021
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