Leaders & Legacies continues with Joy Morton, founder of The Morton Arboretum This photo, circa 1927, shows Joy Morton walking along Joy Path. Courtesy of The Morton Arboretum DuPage Foundation s Leaders & Legacy series In 1923, Joy Morton added a library wing, designed by John Root, to his Thornhill mansion, specifically for Arboretum use. Most of the house was razed in 1941, but the library wing, now called the Founder s Room, was connected to the new Thornhill building. Courtesy of The Morton Arboretum A photo in the DuPage County Centennial Supplement shows author Alice Wood s grandfather, Judge Win G. Knoch, second from right, overseeing the planting of a Zumi crabapple tree at Morton Arboretum during the DuPage County Centennial Celebration in 1939. The Arbor Day event brought together students from every grammar school in DuPage County to plant 200 flowering crabapple trees along the highway passing through the arboretum.