The United States acquired the area of Hawaii through annexation of the Republic of Hawaii on July 7, 1898. Hawaii was officially organized as a territory of the United States on June 14, 1900, with generally the same boundary as the present state. Hawaii was admitted to the Union on August 21, 1959, as the 50^th state.

Census data for Hawaii are available beginning with the 1900 census. The 1910 through 1930 populations do not include Midway Islands, and the 1940 population does not include Baker Island, Canton Island, Enderbury Island, Howland Island, Jarvis Island, Johnston Atoll, and Midway Islands which were enumerated as part of Hawaii Territory even though not legally part of the territory. The 1940 population does include Palmyra Atoll (administratively named Palmyra Island), which was legally part of Hawaii Territory since its organization, but separated from Hawaii upon statehood. (Palmyra Atoll had no population in any other census.) Canton Island and Enderbury Island are now part of the Republic of Kiribati. The other islands and atolls, which are under the jurisdiction of the Department of Interior or the Department of Defense, are part of the U.S. Minor Outlying Islands. For the 1930, 1940, 1950, and 1970 censuses, the population and housing unit data for Kalawao County were included in Maui County. The population and housing unit counts for Kalawao County shown as Kalawao division (CCD) in 1970 was 172 population and 0 (zero) housing units (there are no housing units because the residents were classified as living in a medical facility). The adjusted population for Maui County (including Kalawao County) in 1970 is 45,984. The validity of the urban population reported in Hawaii for 1900, 1910, and 1920 is limited because a place population of 2,500 was required to classify territory as urban, and the Census Bureau did not consistently identify places in Hawaii before 1930.

Data for the legally established state of Hawaii are available beginning with the 1960 census.

There are 75 Hawaiian home lands in the state of Hawaii.  Hawaiian home lands are unique to Hawaii and are lands held in trust for Native Hawaiians by the state, pursuant to the Hawaiian Homes Commission Act of 1920, as amended. 

Metropolitan And Micropolitan Statistical Areas And Related Statistical Areas

Hawaii has one metropolitan statistical area and three micropolitan statistical areas.

Counties

Hawaii has five counties.  Kalawao County, a former leper colony and now a national historic landmark, does not function as a governmental unit and is administered by the State Department of Health.  Honolulu County and city are governmentally consolidated, but through agreement with the State of Hawaii, the Census Bureau does not recognize the city for statistical purposes.

County Subdivisions

There are 44 county subdivisions in Hawaii. 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 Hawaii for the 1960 census.  Prior to 1960, the minor civil divisions used in the census included election districts, voting precincts, and judicial districts.

Places

Hawaii has 151 places; all are census designated places (CDPs).  Hawaii is the only state that has no incorporated places recognized by the Census Bureau.  In agreement with the state, the legal consolidation of Honolulu County and city is not recognized for census purposes except for the Census of Governments.

Census Tracts/Block Groups/Blocks

Hawaii has 351 census tracts, 875 block groups, and 25,016 census blocks.

Congressional Districts

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

School Districts

Hawaii has one unified school district, covering the entire state and administered by the Hawaii Department of Education. 

State Legislative Districts

There are 25 state senate districts and 51 state house districts in Hawaii.  There is one state house district and one state senate district not defined which are comprised solely of water area.

Urban Areas

Hawaii has 23 urban areas; 3 urbanized areas and 20 urban clusters.

Zip Code Tabulation Areas

There are 94 ZIP Code tabulation areas (ZCTAs) in Hawaii. 

Other Information Of General Geographic Interest

The State of Hawaii is composed of seven main inhabited islands—Hawaii, Maui, Lanai, Molokai, Oahu, Kauai, and Niihau--and several smaller uninhabited islands along with the northwestern Hawaiian Islands.  The northwestern Hawaiian Islands are part of the City and County of Honolulu, except for the Midway Islands, which are under the control of the Federal Government and are not part of the state.

Hawaii is the most isolated population center on Earth.  It is 2,390 miles (3,850 km) from California, 3,850 miles (6,195 km) from Japan and 4,900 miles (7,885 km) from China.

¹  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.
²  Source:  U.S. Department of Commerce, Bureau of the Census, Centers of Population for States and Counties, 1974
³  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.
⁴  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.
⁵  Source:  U.S. Census Bureau, computation from national block-level data