Chester County, Pennsylvania: History
Philadelphia, Bucks, and Chester were the three counties created by William Penn on August 24, 1682, in the colonial-era Province of Pennsylvania.
At the time, Chester County's borders were Philadelphia County to the north, the ill-defined western edge of the colony, located approximately at the Susquehanna River to the west, the Delaware River to the east, and Delaware and Maryland to the south. Chester County replaced the Pennsylvania portion of New Netherland's upland in New York, which was officially eliminated when Pennsylvania was chartered on March 4, 1681, and ceased existing in June of that year. Much of the Welsh Tract was in eastern Chester County, and Welsh place names, given by early settlers, continue to predominate there.
The fourth county in the state, Lancaster County, was formed from Chester County on May 10, 1729. On March 11, 1752, Berks County was formed from the northern section of Chester County and parts of Lancaster and Philadelphia counties.
The southern border of Chester County is the Mason–Dixon line, surveyed in 1765. An error in surveying resulted in the Wedge, extending south of the line. Chester County claimed the Wedge until 1921, when it was ceded to Delaware.
The original Chester County seat was the City of Chester, a center of naval shipbuilding, at the eastern edge of the county. In an effort to accommodate the increased population of the western part of the county, the county seat was moved to a more central location in 1788; in order to mollify the eastern portion of the county, the village, known as Turk's Head, was renamed West Chester. In response to the new location of the county seat, the eastern portion of the county separated and formed the new Delaware County in 1789 with the City of Chester as its county seat.
Much of the history of Chester County arises from its location between Philadelphia and the Susquehanna River. The first "road to the West," a reference to Lancaster County, passed through the central part of Chester County, following the Great Valley westward; with some realignments, it became the Lincoln Highway and later U.S. Route 30. This road is still named Lancaster Avenue in most of the Chester County towns it runs through. The first railroad, which became the Pennsylvania Railroad, followed much the same route, and the Reading Railroad progressed up the Schuylkill River to Reading. Industry tended to concentrate along the rail lines. Easy transportation allowed workers to commute to urban jobs, and the rise of the suburbs followed. To this day, the county's developed areas extend along major lines of transportation.
During the American Revolutionary War, the Battle of Brandywine was fought in the southeastern part of the county. The Battle of the Clouds and the Battle of Paoli both took place in the northeastern part of the county, along with George Washington's encampment at Valley Forge.