On a clear September day in 1776, smoke rose from lower Manhattan as the British advanced into the city. From his headquarters on the Morris-Jumel estate, Gen. George Washington may have paused in the shade of a young elm tree to take in the scene.

Today, that tree still stands in what is now Washington Heights, though at about 110 feet tall and almost six feet in diameter, it is doubtful that Washington would recognize it. Affectionately known by locals as "the dinosaur," this living witness to those events 230 years ago it is now one of 25 trees in New York City that will be preserved—through cloning.