The United States acquired almost all the area of New Mexico from Mexico in 1848. The United States acquired a small area, comprising the southwestern corner of New Mexico, from Mexico in 1853 as part of the Gadsden Purchase. New Mexico Territory was organized from the acquired area December 13, 1850, and included most of present-day Arizona and New Mexico as well as parts of Colorado and Nevada. The territory was reduced with the organization of Colorado Territory in 1861 and Arizona Territory in 1863 to assume generally the same boundary as the present state.

Census data are available for New Mexico beginning with the 1850 census. The 1850 census population is for the entire New Mexico Territory, including areas not in present-day New Mexico. For an explanation of the revision to the 1860 population of New Mexico, see Richard L. Forstall, Population of States and Counties of the United States: 1790-1990, Washington, DC: U.S. Government Printing Office, 1996, page 110.

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

American Indian Areas

New Mexico has 23 federally recognized American Indian reservations; 11 with off-reservation trust lands.  There are also two joint-use areas.

Metropolitan And Micropolitan Statistical Areas And Related Statistical Areas

New Mexico has 4 metropolitan statistical areas, 15 micropolitan statistical areas, and 2 combined statistical areas.

Counties

There are 33 counties in New Mexico.  The counties are functioning governmental units, each governed by a board of commissioners.

County Subdivisions

There are 130 county subdivisions in New Mexico. 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 New Mexico for the 1960 census.  Prior to 1960, the minor civil divisions used in the census were election precincts.

Places

New Mexico has 443 places; 102 incorporated places and 341 are census designated places (CDPs).  The incorporated places consist of 35 cities, 19 towns, and 48 villages.  The minimum population required for incorporation is 150. 

Census Tracts/Block Groups/Blocks

New Mexico has 499 census tracts, 1,449 block groups, and 168,609 census blocks.

Congressional Districts

For the 111^th Congress (January 2009-January 2011), New Mexico had three congressional districts.  For the 113^th Congress (January 2013-January 2015), New Mexico continues to have three congressional districts as a result of reapportionment based on the 2010 Census.

School Districts

New Mexico has 89 unified school districts.

State Legislative Districts

There are 42 state senate districts and 70 state house districts in New Mexico.

Urban Areas

New Mexico has 46 urban areas; 6 urbanized areas and 40 urban clusters.

Zip Code Tabulation Areas

There are 372 ZIP Code tabulation areas (ZCTAs).

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