Eleven other historical counties have existed in Massachusetts, most becoming defunct when their lands were absorbed into the colony of New Hampshire or the state of Maine, both of which were created out of territory originally claimed by Massachusetts colonists. The oldest counties still in Massachusetts are Essex County, Middlesex County, and Suffolk County, created in 1643 with the original Norfolk County which was absorbed by New Hampshire and bears no relation to the modern Norfolk County. When these counties were created, they were a part of the Massachusetts Bay Colony, which would remain separate from the Plymouth Colony and that colony's counties until 1691. Hampden County, created in 1812, is the most recently created county still in Massachusetts, although Penobscot County, Maine bore that distinction until Maine broke off from Massachusetts in 1820.[3] The majority of Massachusetts counties are named in honor of English place names, reflecting Massachusetts' colonial heritage.[4]
County
| FIPS Code
[6] | County seat
[7][3] | Established
[7] | Origin
[3] | Etymology
[4] | Population
[7] | Area
[7] | Map
|
| Barnstable County | 001 | Barnstable | 1685 | One of three original counties created in the Plymouth Colony | After its county seat of Barnstable, which is named after the English town of Barnstaple | &0000000000222230.000000222,230 | &0000000000000396.000000396 sq mi
(&0000000000001026.0000001,026 km2) |  |
| Berkshire County | 003 | Pittsfield | 1761 | From part of Hampshire County. Government abolished in 2000.[2] | For the English county of Berkshire | &0000000000134953.000000134,953 | &0000000000000931.000000931 sq mi
(&0000000000002411.0000002,411 km2) |  |
| Bristol County | 005 | Taunton | 1685 | One of three original counties created in the Plymouth Colony | For its original county seat of Bristol, Massachusetts, which is named for the English port city of Bristol - when the city of Bristol joined Rhode Island, the name of the county was kept | &0000000000534678.000000534,678 | &0000000000000556.000000556 sq mi
(&0000000000001440.0000001,440 km2) |  |
| Dukes County | 007 | Edgartown | 1695 | From Martha's Vineyard and the Elizabeth Islands, which had been part of Dukes County, New York until Massachusetts gained it in 1691 | Formerly a part of Dukes County, New York until 1691, the land at one time was literally the possession of the Duke of York | &0000000000014987.00000014,987 | &0000000000000104.000000104 sq mi
(&0000000000000269.000000269 km2) |  |
| Essex County | 009 | Salem and Lawrence | 1643 | One of four original counties created in the Massachusetts Bay Colony. Government abolished in 1999.[2] | For the English county of Essex | &0000000000723419.000000723,419 | &0000000000000498.000000498 sq mi
(&0000000000001290.0000001,290 km2) |  |
| Franklin County | 011 | Greenfield | 1811 | From part of Hampshire County. Government abolished in 1997.[2] | For Benjamin Franklin (1706–1790), early American scientist, diplomat, and politician | &0000000000071535.00000071,535 | &0000000000000702.000000702 sq mi
(&0000000000001818.0000001,818 km2) |  |
| Hampden County | 013 | Springfield | 1812 | From part of Hampshire County. Government abolished in 1998.[2] | Possibly named for John Hampden (1595—1643), the famous 17th century English parliamentarian | &0000000000456228.000000456,228 | &0000000000000618.000000618 sq mi
(&0000000000001601.0000001,601 km2) |  |
| Hampshire County | 015 | Northampton | 1662 | From unorganized territory in the western part of the Massachusetts Bay Colony. Government abolished 1999.[2] | For the English county of Hampshire | &0000000000152251.000000152,251 | &0000000000000529.000000529 sq mi
(&0000000000001370.0000001,370 km2) |  |
| Middlesex County | 017 | Cambridge and Lowell | 1643 | One of four original counties created in the Massachusetts Bay Colony. Government abolished in 1997.[2] | For the former English county of Middlesex | &0000000001456396.0000001,456,396 | &0000000000000824.000000824 sq mi
(&0000000000002134.0000002,134 km2) |  |
| Nantucket County | 019 | Nantucket | 1695 | From Nantucket Island which had been part of Dukes County, New York until Massachusetts gained it in 1691. | The Town of Nantucket | &0000000000009520.0000009,520 | &0000000000000048.00000048 sq mi
(&0000000000000124.000000124 km2) |  |
| Norfolk County | 021 | Dedham | 1793 | From part of Suffolk County. | For the English county of Norfolk | &0000000000650308.000000650,308 | &0000000000000400.000000400 sq mi
(&0000000000001036.0000001,036 km2) |  |
| Plymouth County | 023 | Plymouth and Brockton | 1685 | One of three original counties created in the Plymouth Colony. | For its seat of Plymouth, which is named for the English port city of Plymouth | &0000000000472822.000000472,822 | &0000000000000661.000000661 sq mi
(&0000000000001712.0000001,712 km2) |  |
| Suffolk County | 025 | Boston | 1643 | One of four original counties created in the Massachusetts Bay Colony. Government abolished in 1999.[2] | For the English county of Suffolk | &0000000000689907.000000689,907 | &0000000000000058.00000058 sq mi
(&0000000000000150.000000150 km2) |  |
| Worcester County | 027 | Worcester | 1731 | From parts of Hampshire County, Middlesex County and Suffolk County. Government abolished in 1998.[2] | For its county seat of Worcester, which is named in honor of the English town of Worcester and the English Civil War Battle of Worcester in 1651, a Parliamentarian victory | &0000000000750963.000000750,963 | &0000000000001513.0000001,513 sq mi
(&0000000000003919.0000003,919 km2) |  |
