Barnstable County is a county located in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

, consisting of Cape Cod

Cape Cod

Cape Cod, often referred to locally as simply the Cape, is a cape in the easternmost portion of the state of Massachusetts, in the Northeastern United States...

 and associated islands. (Some adjacent islands are in Dukes County

Dukes County, Massachusetts

-Demographics:As of the census of 2000, there were 14,987 people, 6,421 households, and 3,788 families residing in the county. The population density was 144 people per square mile . There were 14,836 housing units at an average density of 143 per square mile...

 and Nantucket County.) As of the 2010 census, the population was 216,902. Its county seat

County seat

A county seat is an administrative center, or seat of government, for a county or civil parish. The term is primarily used in the United States....

 is Barnstable

Barnstable, Massachusetts

Barnstable is a city, referred to as the Town of Barnstable, in the U.S. state of Massachusetts and the county seat of Barnstable County. Barnstable is the largest community, both in land area and population, on Cape Cod. The town contains seven villages within its boundaries...

.

Barnstable County was formed as part of the Plymouth Colony

Plymouth Colony

Plymouth Colony was an English colonial venture in North America from 1620 to 1691. The first settlement of the Plymouth Colony was at New Plymouth, a location previously surveyed and named by Captain John Smith. The settlement, which served as the capital of the colony, is today the modern town...

 on 2 June 1685, including the towns of Falmouth

Falmouth, Massachusetts

Falmouth is a town in Barnstable County, Massachusetts, United States; Barnstable County is coextensive with Cape Cod. The population was 31,531 at the 2010 census....

, Sandwich

Sandwich, Massachusetts

Sandwich is a town in Barnstable County, Massachusetts, United States. The population was 20,675 at the 2010 census. The Town Hall is located right next to the Dexter Grist Mill, in the historic district of town....

 and others lying to the east and north on Cape Cod.