Original sentence: "  The name "Upper Manhattan" is less commonly used, and "Northern Manhattan" is extremely rare.In Manhattan it can also be a direction, meaning, roughly, "north" or "northbound," as in "I'm going uptown.Uptown includes such neighborhoods as the Upper West Side, Upper East Side, Harlem, Spanish Harlem, Washington Heights, Hudson Heights, Manhattan Valley, Manhattanville, Morningside Heights, Marble Hill, and Inwood
Edited sentence: "  Although geographically accurate, the names "Upper Manhattan" or "Northern Manhattan" are less commonly used.In Manhattan, particularly when one is in roughly the southern half of the borough, it can also mean "north" or "northbound," as in "I'm going uptown.The basis for this distinction lies in economic, ethnic and racial distinctions generally held that contrast the Upper West and East Sides with the neighborhoods north of 96th Street, but still, these classifications are hardly fixed, as gentrification and other factors sometimes add new distinctions and often obliterate old ones.This may largely be the result of the term having a distinct socio-economic connotation referring to Manhattans affluent Upper West and Upper East Side.Though usage is hardly standardized, a distinction is usually made that Upper Manhattan consists of all of Uptown excluding the Upper West Side and Upper East Side proper (having its southern boundary at around 96th Street), while Uptown (under a somewhat simplistic system aiming to locate all of the borough under Uptown, Midtown and Downtown) includes everything north of 59th Street, sometimes even including the Bronx.Uptown includes such neighborhoods as the Upper West Side, Upper East Side (and all sub-neighborhoods within the previous two), Harlem, Spanish Harlem, Washington Heights, Hudson Heights, Manhattan Valley, Manhattanville, Morningside Heights, Marble Hill, and Inwood