The arboretum functions as a major center of botanical research. It was established in 1927 by an act of Congress after a campaign by Botanist Frederick Vernon COVILLE and is 1.78 square kilometres in size. You can find the original columns that supported the old East Portico of the Capitol (they were removed during the expansion project of 1958). Also interesting is the very beautiful and elaborate Bonzai collection. More pix HERE.