Maryland Counties
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Maryland Counties

There are twenty-four counties and county-equivalents in Maryland. Though an independent city rather than a county, the City of Baltimore is considered the equal of a county. The last new county formation in Maryland occurred when Garrett County was formed in 1872 from portions of Allegany County.

St. Mary's County, Maryland

St. Mary's County Education, Geography, and HistorySt. Mary's County, Maryland Courthouse

Saint Mary's County (often abbreviated as St. Mary's County), established in 1637, is a county located in the state of Maryland. Based on the 2010 census, the population was 105,151. Its county seat is Leonardtown. The name is in honor of Mary, the mother of Jesus.

St. Mary's County comprises the California-Lexington Park, MD Metropolitan Statistical Area, which is also included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. It is part of the Southern Maryland region.

Etymology - Origin of St. Mary's County Name

Mary, Lady Somerset, sister-in-law of C?ilius Calvert, 2nd Baron Baltimore


County QuickFacts: CensusBureau Quick Facts

St. Mary's County History

The settlement of Lord Baltimore's Maryland began with the arrival of passengers from England at St. Clement's Island in the Potomac River in what is now southwestern St. Mary's County on March 25, 1634 (the anniversary of this landing being annually celebrated as Maryland Day). The passengers arrived in two vessels, the Ark and the Dove, which had set sail from the Isle of Wight on November 22, 1633. The county is also home to the first Catholic Mass celebrated in one of the original thirteen colonies -after they'd become English colonies (masses were said in 1526-7 at San Miguel de Gualdape).

Due to the small size of the Island, and its lack of resources, the intention was never to make a permanent settlement there. Instead it was used as a base for the settlers while scouting for a more suitable site. This was how a bluff overlooking the nearby St. Marys River was chosen for numerous reasons, and became the site of the first permanent settlement. It would soon be named "St. Marys City".

St. Mary's City, Maryland is the site of the first Maryland Capitol and remained so for over 50 years until 1695, when the capitol was moved to Annapolis.

Today Historic St. Mary's City is a major attraction in Maryland with four museums, a reconstructed colonial village and the reconstructed Maryland Dove settlers ship. It is also now one of the top archeological research sites in North America.

St. Mary's County was the first county established in Maryland, in 1637, probably by an order of the Governor.

Geography: Land and Water

As reported by the Census Bureau, the county has a total area of 764 square miles (1,980 km2), of which 357 square miles (920 km2) is land and 407 square miles (1,050 km2) (%) is water. It is the second-largest county in Maryland by total area.

Located on the St. Mary's Peninsula, St. Mary's County is largely bordered by water: the Patuxent River (northeast), the Chesapeake Bay (east), the Potomac River (southwest), and the Wicomico River (west). Its coastline also has many coves, tidal creeks, bays and inlets. Many coastal areas are made up of mixed clay-and-sand cliffs and bluffs, which protect many parts of the county from storm surges, however there are also low-lying coastal areas with coarse sand or gravel beaches or tidal marshlands.

The interior of much of the county is hilly to varying degrees, with forests and agricultural fields. There are also coastal plain areas, much of which are also under agriculture or under new development. Residential development has been steadily increasing for decades.

The county's very extensive waters are mostly brackish, ranging from significant degrees of saltwater in tidal areas that are on or near the Chesapeake Bay, to a greater predominance of freshwater and lower salt concentrations in its interior tidal waterways and also further up its bordering rivers.

Neighboring Counties

Bordering counties are as follows:

  • North: Calvert County
  • East: Chesapeake Bay
  • South: Potomac River Estuary
  • Northwest: Charles County


  • St. Mary's College of Maryland is in St. Mary's City, Maryland, and has been ranked "6th in the nation" under the category " Public Liberal Arts Colleges" by the US News and World Report 2014 University and College Rankings report.
  • The College of Southern Maryland, in Leonardtown, Maryland.
  • Southern Maryland Higher Education Center in California, Maryland.
  • Paul Hall Center for Maritime Training and Education is a Merchant Marine school in Piney Point, Maryland.

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