Answer Man recounts how Nation's Capital came to be known as the 'City of Trees'; Washington, DC

John Kelly - In its early days, District grew into the 'City of Trees':
Answer Man could not find the precise instant Washington went from being a city of trees to being the City of Trees. Suffice to say that the notion, if not the Chamber of Commerce-esque sobriquet, has deep roots. (Get it?)
'George Washington was a passionate tree lover,' said Melanie Choukas-Bradley, a local author who literally wrote the book on the subject: 'City of Trees: The Complete Field Guide to the Trees of Washington, D.C.'
As Answer Man and Melanie recently emerged from Union Station and caught sight of the gleaming Capitol dome seemingly floating atop clouds of trees, she said: 'The first thing you see is this beautiful green welcoming tree canopy. It's been part of our heritage since Day One.'