As a Quaker, Penn had experienced religious persecution and wanted his colony to be a place where anyone could worship freely.This tolerance, far more than afforded by most other colonies, led to better relations with the local Native tribes and fostered Philadelphia's rapid growth into America's most important city.The Dutch considered the entire Delaware River valley to be part of their New Netherland colony.
By the 1750s, Philadelphia had surpassed Boston to become the largest city and busiest port in British America, and second in the British Empire, behind London.
A number of important philosophical societies were formed, which were centers of the city's intellectual life: the Philadelphia Society for Promoting Agriculture (1785), the Pennsylvania Society for the Encouragement of Manufactures and the Useful Arts (1787), the Academy of Natural Sciences (1812), and the Franklin Institute (1824).
These worked to develop and finance new industries and attract skilled and knowledgeable immigrants from Europe.
which signed the United States Declaration of Independence, during the war; and the Constitutional Convention (1787) after the war.
Several battles were fought in and near Philadelphia as well.
Penn planned a city on the Delaware River to serve as a port and place for government.