New York's Subway Celebrates It's 100th Birthday

On October 27th 2004, New York's subways system celebrated it's centenary. "The creation of the subway led to two events that had profound implications for New York: The first was the decision to move the office of the New York Times from its downtown location, besieged by construction, to a new office on 43rd Street and what was then Longacre Square.
The second was a construction boom in the suburban area of Harlem; real-estate developers began betting that more people would move there and use the new subway. When buyers failed to materialise, the city's black population took advantage of the housing glut, setting the stage for the Harlem Renaissance two decades later."

New York City Transit's web-site also gives more details about the "History of the New York City Subway System".