Delaware County lies in the river and bay drainage area named "Delaware" in honor of Thomas West, 3rd Baron De La Warr, Governor of the nearby English colony of Virginia.
 The land was explored by Henry Hudson in 1609, and over the next several decades it was variously claimed and settled by the Swedes, the Dutch, and the English.
 Its original human inhabitants were the Lenni-Lenape tribe of American Indians.

Once the Dutch were defeated and the extent of New York was determined, King Charles II of England made his grant to William Penn in order to found the colony which came to be named Pennsylvania.
 Penn divided his colony into three counties: Bucks, Philadelphia, and Chester.
 The riverfront land south of Philadelphia, being the most accessible, was quickly granted and settled.
 In 1789, the southeastern portion of Chester County was divided from the rest and named Delaware County for the Delaware River.
Delaware County lies in the river and bay drainage area named "Delaware" in honor of Thomas West, 3rd Baron De La Warr, Governor of the nearby English colony of Virginia.  The land was explored by Henry Hudson in 1609, and over the next several decades it was variously claimed and settled by the Swedes, the Dutch, and the English.  Its original human inhabitants were the Lenni-Lenape tribe of American Indians.
Once the Dutch were defeated and the extent of New York was determined, King Charles II of England made his grant to William Penn in order to found the colony which came to be named Pennsylvania.  Penn divided his colony into three counties: Bucks, Philadelphia, and Chester.  The riverfront land south of Philadelphia, being the most accessible, was quickly granted and settled.  In 1789, the southeastern portion of Chester County was divided from the rest and named Delaware County for the Delaware River.
Delaware County, Pennsylvania