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
New York–Pennsylvania border New York–Pennsylvania border The New York–Pennsylvania border is the state line between the U.S. states of New York and Pennsylvania. It has three sections: The survey of the 42nd parallel north was carried out in 1785–86 and accepted by the two states in 1787. The surveying technique that was used at the time was not especially accurate, and as such, this boundary wanders a bit on both sides of the true parallel. The 82nd mile stone was used as the starting point of the Preemption Line defined in the Treaty of Hartford in 1786 to separate Massachusetts and New York