The area of Massachusetts was part of the original territory of the United States. It was originally included in the Charter of New England in 1620; the Charter of Massachusetts Bay, which became the Constitution of the Massachusetts Bay Colony in 1629; and a charter that united the Massachusetts Bay and Plymouth colonies in 1691. In 1785, it ceded area to the United States that became part of the Northwest Territory in 1787. Massachusetts ratified the U.S. Constitution on February 6, 1788; it was the sixth of the original 13 states to join the Union. At the time of statehood, the area of Maine was a district in Massachusetts. In 1819, it agreed to allow its district of Maine to petition for statehood, and Maine was admitted to the Union as a separate state on March 15, 1820. There were changes to the boundary between Connecticut and Massachusetts in 1804 and between Rhode Island and Massachusetts in 1862, and a resurvey of the latter boundary in 1897, resulting in generally the same boundary as the present state. Massachusetts is one of four states that are legally described as a commonwealth.

Census data for Massachusetts are available beginning with the 1790 census. The population data for 1790, 1800, and 1810 do not include the area of Maine. The population of the legal area of Massachusetts including the area of Maine for those censuses was 700,745 in 1810; 574,564 in 1800; and 475,327 in 1790.

American Indian Areas

Massachusetts has one state recognized American Indian reservation and one federally recognized trust land. 

Metropolitan And Micropolitan Statistical Areas And Related Statistical Areas

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

There are six metropolitan statistical areas, three metropolitan divisions, one combined statistical area, eight metropolitan NECTAs, four micropolitan NECTAs, nine NECTA divisions, and four combined NECTAs.

Counties

There are 14 counties in Massachusetts.  Barnstable, Bristol, Dukes, Norfolk, and Plymouth counties have active county governments, each governed by a board of county commissioners.  Nantucket County and Nantucket town are governmentally consolidated and have a single set of officials.  Suffolk County and Boston city are governmentally consolidated and have a single set of officials.  Berkshire, Essex, Franklin, Hampden, Hampshire, Middlesex, and Worcester counties are no longer legal governmental units.

County Subdivisions

There are 357 county subdivisions in Massachusetts known as minor civil divisions (MCDs). There are 298 towns with functioning, but not necessarily active, governments. The 53 incorporated places are independent of MCDs and serve as county subdivisions.  In addition there are six MCDs each consisting entirely of water area within the territorial limits of Massachusetts.  In Massachusetts, towns and cities are usually the main providers of local government services.  The entire state is covered by town governments with the exception of the areas within cities.  The governing body in each town and city is the board of selectmen.

Places

Massachusetts has 244 places; 53 incorporated places and 191 census designated places (CDPs).  The incorporated places are all cities.  The minimum population for incorporation in Massachusetts is 12,000.  Cities are governed by a board of selectmen.  An incorporated place can legally exist in a single county only.  All of the incorporated places are cities that are each independent of any other county subdivision and serve as county subdivisions. 

Census Tracts/Block Groups/Blocks

Massachusetts has 1,478 census tracts, 4,985 block groups, and 157,508 census blocks.

Congressional Districts

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

School Districts

Massachusetts has 71 elementary school districts, 35 secondary school districts, and 210 unified school districts.

State Legislative Districts

There are 40 state senate districts and 160 house districts in Massachusetts.  In addition, there is one state senate district and one state house district not defined, each of which encompasses water area.

Urban Areas

Massachusetts has 20 urban areas; 9 urbanized areas and 11 urban clusters.

Zip Code Tabulation Areas

There are 538 ZIP Code tabulation areas (ZCTAs) in Massachusetts.

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