In 1664, the Duke of York sold New Jersey, or "Nova Caesaria" to Lord Berkley and Sir George Carteret.
East Jersey: Carteret's Trustees sold a "Half" in 1682 to twelve associates, thereafter proprietors of East Jersey.
West Jersey: Berkley sold a "Half" in 1673 to associates of the Society of Friends, thereafter proprietors of West Jersey.
Location of a line between the "Halves" persisted in convention. Although not final, the Keith Line of 1687 permanently influenced the structure of New Jersey. Extending from "Little Egg Harbour on a straight line to the Delaware River" NNW and 50' more westerly, this line is perpetuated by Province Line Road, and bounds, in part, Hunterdon, Somerset, Mercer, Monmouth, Burlington, and Ocean Counties.
Title remained in the proprietors, but government of both provinces returned to the British Crown in 1702. Finally resolved by the American War for Independence.