The youngest man to hold this position defeated machine politician John Hylan in a World War I era e
The youngest man to hold this position defeated machine politician John Hylan in a World War I era election.  This first holder of this position after the polity it governs was consolidated created its public transportation system and is Robert Van Wyck. In addition to John Mitchel, the first and only black man to serve in this position was David Dinkins. The holder of this position is entitled to live in a house located in Carl Schurz Park, called Gracie Mansion. A former holder of this position co-sponsored a bill with Norris that outlawed yellow dog contracts. For 10 points, name this position  held by people like Fiorello La Guardia, Rudy Giuliani, and Michael Bloomberg.
The youngest man to hold this position defeated machine politician John Hylan in a World War I era election.  
{Mayor} of {New York City} [prompt on partial answer; accept {logical} equivalents]