| County |
Date formed |
Notes |
| St. Mary's |
1637 |
the first Maryland county, was established in 1637, probably by an order of the Governor |
| Kent |
1642 |
first mentioned as a county in 1642, when the Governor and Council appointed commissioners for the Isle and County of Kent.Commission issued to Commander, Aug. 2, 1642 (Archives of Maryland 3:105) |
| Anne Arundel |
1650 |
created in 1650 (Chapter 8, Acts of 1650, April Session) |
| Calvert |
1654 |
established 1654 by an Order in Council and called Patuxent County until 1658 (Archives of Maryland 3:308) |
| Charles |
1658 |
created in 1658 by an Order in Council. It is not to be confused with an earlier Charles County (1650-1653) known as Old Charles County (Archives of Maryland 3:341) |
| Baltimore |
1660 |
The legal origin of Baltimore County is not known, but it was in existence by January 12, 1659/60 when a writ was issued to the sheriff of the county |
| Talbot |
1662 |
probably formed by virtue of an order of the Governor in Council. The County was in existence by February 18, 1661/62, when a writ was issued to the sheriff |
| Somerset |
1666 |
created by an Order in Council in August 22, 1666 (Archives of Maryland 3:553) |
| Dorchester |
1669 |
The exact date and legal origin of Dorchester County are unknown, but it was in existence by February 16, 1668/69, when a writ was issued to the county sheriff by the Lord Proprietary |
| Cecil |
1674 |
formed in 1674 from Baltimore and Kent counties by proclamation of the Governor |
| Prince George's |
1695 |
formed from Calvert and Charles counties in 1695 (Chapter 13, Acts of 1695, May Session) |
| Queen Anne's |
1706 |
formed in 1706 (Chapter 3, Acts of 1706) |
| Worcester |
1742 |
created from Somerset County in 1742 (Chapter 14, Acts of 1742 |
| Frederick |
1748 |
created in 1748 from Baltimore and Prince George's counties (Chapter 15, Acts of 1748) |
| Harford |
1773 |
formed from Baltimore County in 1773 (Chapter 6, Acts of 1773) |
| Caroline |
1773 |
created in 1773 from Dorchester and Queen Anne's counties (Chapter 10, Acts of 1773) |
