 It was William Penn's desire, as a Quaker, that his "Holy Experiment" would be found blameless at the Last Judgment.When established, Philadelphia County consisted mainly of the area from the Delaware River west between the Schuylkill River to the south and the border with Bucks County to the north; the western boundary was undefined.Two counties would be formed out of Philadelphia County, Berks County which was formed during 1752 (from parts of Chester, Lancaster, and Philadelphia counties), and Montgomery County established during 1784.