The Proprietary House was the residence of William Franklin, the last appointed Royal Governor of New Jersey. William Franklin and his wife lived in the house from 1774 to 1776.

Constructed in 1762 to 1764, it was designed by well-known architect John Edward Pryor. However, it did not gracefully withstand time as vacancy, fire, vandalism, and depression affected the glory of the house over the centuries. Despite its decline, it managed to be the only remaining Royal Governor?s Mansion among the original colonies.

The property was passed on to the State of New Jersey in 1967. It underwent major restoration and preservation measures led by the Proprietary House Association. Today, a part of it serves as a museum while the rest are occupied by professional offices.