The area of Maryland was part of the original territory of the United States. It was chartered as a colony in 1632. The area described by this charter, however, conflicted with the charter for Virginia and, later, the charter for Pennsylvania. Virginia relinquished its claims in 1658, and the Pennsylvania boundary was resolved with the survey of the Mason and Dixon Line in the 1760s. Maryland ratified the U.S. Constitution on April 28, 1788; it was the seventh of the original 13 states to join the Union. Its area was reduced with the cession in 1788 and formation in 1791 of the District of Columbia, resulting in generally the same boundary as the present state.

Census data for Maryland are available beginning with the 1790 census. The population reported for 1790 includes the area subsequently in the District of Columbia.

Metropolitan And Micropolitan Statistical Areas And Related Statistical Areas

Maryland has six metropolitan statistical areas, four micropolitan statistical areas, three metropolitan divisions, and three combined statistical areas.

Counties

There are 24 counties and equivalents in Maryland.  The 23 counties are all functioning governmental units.  Baltimore city is an independent city that functions governmentally at the place level but is also considered a county equivalent.  Baltimore city and Baltimore County are two separate entities covering different area in Maryland and should not be confused with each other.  Anne Arundel, Baltimore, Harford, Howard, Montgomery, Prince George’s, Talbot and Wicomico counties are each governed by a county council.  All other counties are each governed by a board of county commissioners.

County Subdivisions

There are 290 county subdivisions in Maryland known as minor civil divisions (MCDs).  All of the MCDs are nonfunctioning nongovernmental subdivisions of a county, used for conducting elections or recording properties.  The 289 MCDs in 23 counties in Maryland are election districts. Baltimore city is independent of any MCD and serves as a county subdivision.

Places

Maryland has 518 places; 157 incorporated places and 361 census designated places (CDPs).  The incorporated places consist of 29 cities, 123 towns, and 5 villages.  Incorporated places are dependent within county subdivision with the exception of Baltimore city which is independent of any county and county subdivision.  Cumberland city contains one whole election district and parts of six others.   Hagerstown contains four whole election districts and part of six others. Annapolis city legally can exist in only one election district.

Census Tracts/Block Groups/Blocks

Maryland has 1,406 census tracts, 3,926 block groups, and 145,247 census blocks.

Congressional Districts

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

School Districts

Maryland has 24 unified school districts.  The school districts in Maryland are coextensive with counties and equivalent.

State Legislative Districts

There are 47 state senate districts and 65 state legislative districts or subdistricts in Maryland.  In addition, there are 17 undefined state legislative districts and 17 undefined state senate districts which are comprised of water area.

Urban Areas

Maryland has 43 urban areas; 11 urbanized areas and 32 urban clusters.

Zip Code Tabulation Areas

There are 468 ZIP Code tabulation areas (ZCTAs) in Maryland.

Other Information Of General Geographic Interest

Maryland’s boundary with Virginia and part of West Virginia follows the south shore of the Potomac River; the Mason-Dixon Line forms Maryland’s boundary with Pennsylvania and Delaware.

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