On Jan. 1, 2002, when Michael Bloomberg was sworn into office, these things barely existed: iPods, Blackberries, pocket digital cameras. These things didn't exist at all: the Barclays Center, Citi Field, One World Trade, or the Gehry NY building.

People smoked, all the time, in restaurants and bars. Almost no one rode bikes, and T.V.-less yellow cabs drove down Broadway right through Times Square. Back then, a market rate apartment in Harlem was about $1,200 — about half of what it is today. Pizza was $1.50 a slice, same price as a subway token.

Carrie Bradshaw lived in a Manhattan brownstone, drank cosmopolitans and typed onto a black and white computer screen. The High Line was a rusted and weedy hulk, not the locale for furtive kisses for the "Girls" crew before they head home to Brooklyn. Adlai Stevenson High School still existed. The Success Academy and six hundred other schools did not.

You could be anonymous in 2001. Now, not so much. We are watched, everywhere, if not by security cameras, then by each other. 

New York has been transformed in the last 12 years, in ways that are wrenching and huge and intimate.

And though he isn't responsible for all the revolutions we've experienced, Michael Bloomberg leaves an indelibly large mark, both for his outsize personality and his vast reserves of power. In this hour, we take a look.

Technical Direction by Paul Schneider and George Wellington