List of Massachusetts counties

List of Massachusetts counties:

1. Barnstable County: one of three original counties created in the Plymouth Colony in 1685. County seat: Barnstable.
2. Berkshire County: formed in 1761 from part of Hampshire County. County seat: Pittsfield.
3. Bristol County: one of three original counties created in the Plymouth Colony in 1685. County seat: Taunton.
4. Dukes County: formed in 1695 from Martha's Vineyard and the Elizabeth Islands, which had been part of Dukes County, New York until Massachusetts gained it in 1691. County seat: Edgartown.
5. Essex County: one of four original counties created in Massachusetts in 1643. County seat: Salem.
6. Franklin County: formed in 1811 from part of Hampshire County. County seat: Greenfield.
7. Hampden County: formed in 1812 from part of Hampshire County. County seat: Springfield.
8. Hampshire County: formed in 1662 from the western part of Massachusetts. County seat: Northampton.
9. Middlesex County: one of four original counties created in Massachusetts in 1643. County seat: Cambridge.
10. Nantucket County: formed in 1695 from Nantucket Island which had been part of Dukes County, New York until Massachusetts gained it in 1691. County seat: Nantucket.
11. Norfolk County*: formed in 1793 from part of Suffolk County. County seat: Dedham.
12. Plymouth County: one of three original counties created in the Plymouth Colony in 1685. County seat: Plymouth.
13. Suffolk County: one of four original counties created in Massachusetts in 1643. County seat: Boston.
14. Worcester County: formed in 1731 from parts of Hampshire County, Middlesex County, and Suffolk County. County seat: Worcester.

*The original Norfolk County was formed in 1643 and included the territory in Massachusetts north of the Merrimack River and west of the district of Maine. In 1679 the county was eliminated when most of the county became part of the colony of New Hampshire and the remainder was added to Essex County. It was unconnected to the current Norfolk County.