why is part of delaware in new jersey
New Jersey v. Delaware Jurisdiction over rivers that form a border between states is usually determined by dividing the river down the middle between the states; this is not the case with the Delaware River. Delaware-New Jersey's curious border is the result of a grant by King Charles II in 1681, when the Delaware Colony was leased by William Penn from King Charles to become the three lower counties of Pennsylvania. The grant extended Delaware's northern border by The Twelve-Mile Circle in New Castle, Delaware, extending across the Delaware River. If the circle were to be extended fully, it would have included a portion of New Jersey, but this was unacceptable because that land had already been granted. As a result, the 12-Mile-Circle terminated at the mean low water mark on New Jersey's shore. The post-1681 border gave present-day Delaware full ownership of the Delaware River along a stretch of the New Jersey border.