Today’s Maryland counties did not always exist in the present form. They went through many different changes in the space of a few short years.

Province of Maryland Counties

The Province of Maryland was established on June 22, 1632. The first settlement and capital was St. Mary’s City, in Saint Mary’s County.

The State of Maryland entered the union as the 7th state on April 28, 1788 with a total of 17 counties.

Maryland Counties Today

Today, Maryland is divided into 23 counties and the City of Baltimore. States bordering Maryland are  DelawarePennsylvaniaVirginiaWest Virginia and the District of Columbia.

Outside of Baltimore (which is an independent city) the county is the default unit of local government. Under Maryland law, counties exercise powers reserved in most other states at the municipal or state levels, so there is little incentive for a community to incorporate.

The City of Baltimore generally possesses the same powers and responsibilities as the counties within the state. It is an entity nearly surrounded by but separate from the County of Baltimore, which has its county seat in Towson.

Though an independent city rather than a county, the City of Baltimore is considered the equal of a county for most purposes and is a county-equivalent.

Fun Facts about Maryland Counties

County Names

Many of the counties in Maryland were named for relatives of the Barons Baltimore who were the proprietors of the Maryland colony from its founding in 1634 through 1771.

Counties by Year

County Size Facts

County Population Facts

Maryland City Facts

Maryland’s 10  largest cities (2010) are:

  1. Baltimore (620,961) is an Independent City
  2. Frederick (620,961) is in Frederick County
  3. Rockville (61,209) is in Montgomery County
  4. Gaithersburg (59,933) is in Montgomery County
  5. Bowie (54,727) is in Prince George’s County
  6. Hagerstown (39,662) is in Washington County
  7. Annapolis (38,394) is in Anne Arundel County
  8. College Park (30,413) is in Prince George’s County
  9. Salisbury (30,343) is in Wicomico County
  10. Laurel (25,115) is in Prince George’s County

Boundary Changes of Maryland Counties from 1637-1997

This Interactive Map of Maryland Counties show the historical boundaries, names, organization, and attachments of every county, extinct county and unsuccessful county proposal from 1637 to 1997.

List of Maryland Counties

List of Old Former / Extinct Maryland Counties

There are some Maryland counties that no longer exist because they were discontinued, renamed or merged with another county. These are important for genealogy research purposes.

The below Maryland counties no longer exist:

Charles County (Old), Province of Maryland

Created on Novewmber  21, 1650 from from part of Saint Mary’s County. The County was named in honor of King Charles I of England.

Charles County was dissolved on July 3, 1654. Referred to as Old Charles County. Part of the area was incorporated into Calvert County.

The new Charles County was re-created April 13, 1658 the area just west of Calvert County and at the time included the area that is now Prince George’s County.

Durham County, Province of Maryland

Durham County was a new county created on the previously neglected oceanside of the Maryland Colony on October 22, 1669 from part of Somerset County and nonorganized territory.

It was Abolished on June 19, 1672 and incorporated in Worcester County.

Durham County, Maryland was in what is now southern half of Kent County, Delaware, and northern half of Sussex County, Delaware (claimed for a short while by New Netherland, and then by Maryland, and Pennsylvania).

47 new land grants for Maryland were granted in Durham County as late as 1682, although Durham County should have been incorporated into old Worcester County, Maryland in 1670.

In 1738 Maryland recognized the claim of Pennsylvania to the lower three counties on the Delaware River (now the State of Delaware) including what was once all of Durham County, or later part of old Worcester County, Maryland.

Patuxent County, Province of Maryland

Created on October 20, 1654 , when Calvert County was renamed. On March 24, 1658, Patuxent County was renamed back to Calvert County.

Potomac County, Province of Maryland

Created on October 20, 1654 , when Saint Mary’s County was renamed. On March 24, 1658, Potomac County was renamed back to Saint Mary’s County.

Providence County, Province of Maryland

Created on October 20, 1654, when Anne Arundel County was renamed. On March 24, 1658, Providence County was renamed back to Anne Arundel County.

Worcester County (Old), Province of Maryland

Worcester County was created on June 19, 1672 from part of Durham County and he previously neglected ocean side of Maryland, after a November 26, 1669 surveyor report of Dutch encroachment at Cape Henlopen (New Netherland).

The county was named in honor of Mary Arundell, the wife of Sir John Somerset, son of the 1st Marquess of Worcester,
and sister of Anne Arundell, wife of Cecil Calvert, 2nd Baron Baltimore.

Old Worcester County, Maryland extended along the entire Atlantic coast between Virginia (southern most branch of Rehobeth Bay) and Pennsylvania. This included all of the present day State of Delaware.

In 1674, at the end of an Anglo-Dutch war, the Duke of York assumed authority over the Delaware part of New Netherland which overlapped Lord Baltimore’s sparsely settled Maryland claim.

In 1682 the Duke of York paid an old debt by giving his claim of Delaware’s lands to William Penn. Penn immediately declared an act of union between the Delaware counties and Pennsylvania.

Worcester County was located in present Delaware and Pennsylvania and never became operational.

On November 13, 1685 King James II approved the decision of the Committee for Trade and Plantations (November 7, 1685) settling the rival claims of Maryland and Pennsylvania to Pennsylvania‘s Lower Counties, now Delaware.

The committee concluded that the west side of Delaware Bay was outside the grant to Lord Baltimore. Where the boundary line should run was not settled until 1760, the decree resulted in the end of old Worcester County. Full provisions and acceptance of this decree were delayed until 1738.

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