| "Western" is defined as west of Chesapeake Bay and Cecil
Co. (i.e., mainland Maryland) |
| |
| YEAR |
CHANGE: when a
county reaches its 1997 form, its name is highlighted in red. |
| 1637 |
Formation of St. Marys Co., the first and only county in MD until 1642 |
| 1642 |
Kent Co. formed from St. Marys Co. |
| 1650 |
Anne Arundel and "old" Charles Cos. formed from St. Marys Co. |
| 1654 |
Patuxent Co. formed from all of "old" Charles Co. and part of St. Marys
Co. |
| Name of Anne Arundel Co. changed to Providence Co. |
| Name of St. Marys Co. changed to Potomac Co. |
| At this point, Anne Arundel, St. Marys, and "old" Charles
Cos. have ceased to exist |
| 1658 |
"new" Charles Co. formed from part of Potomac Co. |
| Name of Patuxent Co. changed to Calvert Co. |
| Name of Providence Co. changed back to Anne Arundel Co. |
| Name of Potomac Co. changed back to St. Marys Co. |
| At this point, Anne Arundel and St. Marys Cos. have been
resurrected as they were before the name changes four years previous (though
St. Marys Co. is smaller due to the formation of the new Charles Co.);
however, the new Charles Co. is not the old one. The "old"
Charles Co. bordered on Chesapeake Bay, roughly equivalent to (though somewhat
larger than) today's Calvert Co. The "new" Charles Co. is west of
the old one and borders with Virginia, in what was once part of the original
St. Marys Co. |
| 1659 |
Baltimore Co. formed mostly de novo, but in small part from
Anne Arundel and Kent Cos. |
| 1674 |
Cecil Co. formed from Baltimore Co. |
| 1695 |
Prince Georges Co. formed mostly de novo, but in part from Charles
and Calvert Cos. |
| 1696 |
St. Marys Co. and Charles Co. gained from
Calvert Co. |
| 1698 |
Anne Arundel Co. and Baltimore Co. exchange land |
| 1727 |
Anne Arundel Co. gained from Baltimore Co. |
| 1748 |
Frederick Co. formed mostly de novo, but in part from Prince
Georges Co. |
| Charles Co. gained from Prince Georges
Co. |
| 1750 |
Frederick Co. gained from Baltimore Co. |
| 1773 |
Harford Co. formed from Baltimore Co. |
| 1776 |
Washington and Montgomery Cos. formed from Frederick Co. |
| 1789 |
Allegany Co. formed from Washington Co. |
| 1791 |
District of Columbia formed from Montgomery and Prince Georges Cos. |
| 1824 |
Calvert Co. gained from
Anne Arundel Co. |
| 1837 |
Carroll Co. formed from Frederick
Co. and Baltimore Co. |
| 1851 |
Howard Co. formed from Anne
Arundel Co.
Baltimore City becomes independent from Baltimore
Co. |
| 1872 |
Garrett Co. formed from Allegany
Co. |
| 1888 |
Baltimore City gained from Baltimore Co. |
| 1918 |
Baltimore City gained from Baltimore
Co. |
| 1997 |
Montgomery Co. gained (very slightly)
from
Prince Georges Co. |
| |
|
| Source: AniMapPlus:
County Boundary Historical Atlas.
Gold
Bug Software, Alamo, CA. |
| |