New York City worldwide. New York City is situated in the Northeastern United States, in southeastern New York State, approximately halfway between Washington, D.C. and Boston. The location at the mouth of the Hudson River, which feeds into a naturally sheltered harbor and then into the Atlantic Ocean, has helped the city grow in significance as a trading port. Most of New York City is built on the three islands of Long Island, Manhattan, and Staten Island. The Hudson River flows through the Hudson Valley into New York Bay. Between New York City and Troy, New York, the river is an estuary. The
East Coast of the United States edge and one on the eastern edge. Other terms for referring to this area include the "Eastern Seaboard" ("seaboard" being American English for coast), "Atlantic Coast", and "Atlantic Seaboard" (because the coastline lies along the Atlantic Ocean). The fourteen states that have a shoreline on the Atlantic Ocean are, from north to south, the U.S. states of Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and Florida. In addition, Pennsylvania and the District of Columbia border tidal arms of the Atlantic (the Delaware River and the Potomac River, respectively).