|Chester County, Pennsylvania| Location in the state of
Pennsylvania Pennsylvania's location in the U.S. |Largest
city||West Chester| 760 sq mi (1,968 km²) 756 sq mi (1,958 km²)
4 sq mi (10 km²), 0.51% 660/sq mi (254.7/km²) Chester County is
a county located in the U.S. state of Pennsylvania. As of the
2010 census, the population was 498,886, with an estimated
population of 500,182 in 2011. The county seat is West Chester.
It is the highest-income county in Pennsylvania and 24th highest
in the nation as measured by median household income (as of
2010). Eastern Chester County is home to many communities that
comprise the Main Line western suburbs of Philadelphia, while
part of its southernmost portion is considered suburban
Wilmington, Delaware, along with southwest Delaware County.
Chester County was one of the three original Pennsylvania
counties created by William Penn in 1682. It was named for
Chester, England. It is part of the Delaware Valley region and
is the only county in Philadelphia's Pennsylvania s