In 1681, Penn became the owner of Pennsylvania because:

William Penn (1644-1718), founder of Pennsylvania. Son of an admiral, he was sent to a Puritan school and was expelled
from Oxford as a dissenter in 1660. Sent to Ireland to manage the family estates, he regularly attended the Quaker meeting at Cork,
and on his return to England he was twice imprisoned for proselytizing, but nonetheless retained connections with the court. In
1681, Charles II repaid a debt owed to Penn's father by granting him a large province on the west bank of the Delaware river in
North America. Penn drew up a frame of government providing for religious toleration in the new colony, which he named
Pennsylvania. After he had supervised the building of Philadelphia (1682-4), he returned to England and, on James II's accession,
secured the release of some 1,200 Quaker prisoners. Out of favour after the Glorious Revolution, he returned to America in 1699,
but financial mismanagement forced him to mortgage his rights as proprietor of the colony.

(Gardiner, J., & Wenborn, N. (eds.) (1995). The History Today Companion to British History. London: Collins & Brown.)