 Complete the following phrase:  As the fur trade expanded further north, New York became a trading hub, which brought in a diverse set of ethnic groups including Africans, Jews, and Portuguese. The island of Manhattan had an extraordinary natural harbor formed by New York Bay actually the drowned lower river valley of the Hudson River, enclosed by glacial moraines, the East River actually a tidal strait, and the Hudson River, all of which merge at the southern tip, from which all later development spread. During the American Revolution, the strategic waterways made New York vitally important as a wartime base for the British navy. Many battles such as the Battle of Long Island and the 