Last week the new Rockefeller Center Christmas Tree arrived at 30 Rock after being torn from its roots in Easton, Connecticut. It will now have until December 2nd to be adorned with lights (last year folks were not impressed by the energy-efficient LED lights), before being plugged in for holiday revelers to enjoy. Here's some history on the tree tradition, which started about 77 years ago — and a look back at trees of the past (in 1938 there were two!).