Maine was originally part of Massachusetts. It was included in the Charter of New England in 1620 and the Charter of Massachusetts Bay in 1629; the latter became the Constitution of the Massachusetts Bay Colony, predecessor to the Commonwealth of Massachusetts. In 1819, Massachusetts agreed to allow its district of Maine to petition for statehood. Maine was admitted to the Union as a separate state on March 15, 1820, as the 23^rd state. The state’s boundary with Canada was not formally established until the Webster-Ashburton Treaty of 1842, when Maine assumed generally the same boundary as the present state.

Census data for Maine are available beginning with the 1790 census. Maine was enumerated as a separate district within the state of Massachusetts in the 1790, 1800, and 1810 censuses. Presentation of data as a separate state began with the 1820 census. The population of the legal area of Massachusetts (of which the area of Maine was a part) was 700,745 in 1810; 574,564 in 1800; and 475,327 in 1790.

Data for the legally established state of Maine are available beginning with the 1820 census.

American Indian Areas

Maine has six federally recognized American Indian areas.  There are four reservations, two with off-reservation trust land.  There are also two trust lands.

Metropolitan And Micropolitan Statistical Areas And Related Statistical Areas

Maine has core based statistical areas based on both counties (metropolitan statistical areas, micropolitan statistical areas, and combined statistical areas) and county subdivisions (metropolitan New England city and town areas (NECTAs), micropolitan NECTAs, and combined NECTAs).

Maine has three metropolitan statistical areas, two micropolitan statistical areas, one combined statistical area, five metropolitan NECTAs, five micropolitan NECTAs, and three combined NECTAs.

Counties

There are 16 counties in Maine.  Each county is governed by a board of county commissioners. 

County Subdivisions

There are 533 county subdivisions in Maine known as minor civil divisions (MCDs).  There are 433 towns which are functioning governmental units, each governed by a board of selectmen.  There are 34 plantations which are functioning but not necessarily active governmental units, each governed by a board of assessors.  There is one gore which is a nonfunctioning nongovernmental geographic subdivision of a county.  There are three American Indian reservations that constitute four county subdivisions.  There are 22 incorporated places which are independent of any other MCD and treated as MCD equivalents.  There are also 39 unorganized territories. 

Places

Maine has 131 places; 22 incorporated places and 109 census designated places (CDPs).  The incorporated places are all cities.  In Maine, incorporated places are independent of county subdivisions.  An incorporated place in Maine can legally exist in only a single county.  The 22 incorporated places create 22 county subdivisions.  Cities and MCDs have similar governmental functions, each governed by a board of selectmen.

Census Tracts/Block Groups/Blocks

Maine has 358 census tracts, 1,086 block groups, and 69,518 blocks.

Congressional Districts

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

School Districts

Maine has 5 elementary school districts, 4 secondary school districts, and 240 unified school districts.

State Legislative Districts

There are 35 state senate districts and 151 state house districts in Maine.  In addition, there is one state senate district and one state house district not defined which is comprised of water area.

Urban Areas

Maine has 26 urban areas; 5 urbanized areas and 21 urban clusters.

Zip Code Tabulation Areas

There are 433 ZIP Code tabulation areas (ZCTAs) in Maine.

Other Information Of General Geographic Interest

Maine is the most sparsely populated state east of the Mississippi River.

Maine is the only state that borders only one other state.

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