New Jersey is a state in the Mid-Atlantic region of the Northeastern United States. New Jersey's a peninsula, bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware River and Pennsylvania; and on the southwest by the Delaware Bay and Delaware. New Jersey is the fourth-smallest state by area but the 11th-most populous, with 9 million residents as of 2017, and the most densely populated of the 50 U.S. states. New Jersey lies completely within the combined statistical areas of New York City and Philadelphia and is the third-wealthiest state by median household income as of 2016.New Jersey was inhabited by Native Americans for more than 2,800 years, with historical tribes such as the Lenape along the coast. In the early 17th century, the Dutch and the Swedes made the first European settlements in the state.