As Thomas did not have any sons while John Penn was in his youth, the younger man was in line to inherit the entire proprietorship, one-fourth from his father and three-fourths from his paternal uncle.

Apparently regretting his marriage, Penn made no effort to contact Grace during this period.

In 1754, Penn attended the Albany Congress with Pennsylvania's other delegates, including Peters, Benjamin Franklin, and Isaac Norris.

From his home in England, the chief proprietor Thomas Penn soon became alarmed at John's extravagant expenses.

The Penns were not displeased with Hamilton but believed that John was prepared to assume leadership in the province for the family.

The new governor faced many challenges: Pontiac's Rebellion; the Paxton Boys; border disputes with other colonies; controversy over the taxation of Penn family lands; and the efforts of the Pennsylvania Provincial Assembly, led by Benjamin Franklin, to have the Penn proprietary government replaced with a royal government.

The Penns were slow to perceive that the growing unrest, which became the American Revolution, would threaten their proprietary interests.

[7] Henry J. Cadbury states, "The end of proprietary government in Pennsylvania may be dated Sept. 26, 1776, with the last adjournment of the provincial assembly.

With no power at his command, Penn remained aloof and carefully neutral in the hope that the radicals would be defeated or at least reconciled with the king.

As Howe's army drew close, the Patriots threatened Penn with exile to another colony, and he then signed the parole.

The new government of Pennsylvania required all residents to take a loyalty oath to the Commonwealth or to face confiscation of their property.

Failing there, they traveled to England in 1789 to seek compensation from Parliament, which awarded the Penn cousins a total of £4,000 per year (equal to £621,093 today) in perpetuity.

[13] Penn "of Stoke" stayed in England for the rest of his life, serving as a member of parliament in the early 1800s.

Returning to Pennsylvania, John Penn lived the rest of his life with his family quietly in Lansdowne.