Island (pop., 2000: 9,520), Atlantic Ocean, south of Cape Cod , Mass.
, U.S. It is separated from Martha's Vineyard by the Muskeget Channel. Of glacial origin, it has sandy beaches, a good harbour, and a moderate climate. Purchased from the Plymouth colony in 1641, it became part of New York and was settled in 1659 by Quakers, then ceded to Massachusetts in 1692. It was a whaling centre in the 18th century. The summer tourist trade is now its economic mainstay.