On March 4, 1681, King Charles II granted William Penn a charter for a new American colony. Pennsylvania was to be, in its founder's words, a bold "Holy Experiment" in religious freedom and toleration, a haven for those fleeing persecution in an increasingly intolerant England and across Europe. An activist, political theorist, and the proprietor of his own colony, Penn would become a household name in the New World, despite spending just four years...