Original sentence: Marble Hill is part of the borough of  Manhattan (and New York County) but is no longer on Manhattan Island
Edited sentence: Marble Hill is legally a part of Manhattan (and New York County) but is no longer on Manhattan Island.Mostly of Dominican decent.The area is largely lower-middle to middle class in character and is home to many people of Hispanic background.Up the hill, several thousand feet to the north and west of the area, is the suburban and mostly white area of Riverdale, which is the most affluent section of the Bronx