He was absent two years, and coming home in 1842, soon arranged for another term of travel abroad. He remained in Europe three years, travelling in almost all places of interest, including Constantinople and Egypt. He kept journals, and wrote letters to friends, showing careful observation and wide reading. He made a third and last visit to Europe in 1851, to attend the first World's Fair, held in London. During this visit he conceived the plan of what eventually became his great gift. While walking through the beautiful grounds of Chatsworth, the magnificent home of the Duke of Devonshire, Mr. Shaw said to himself, "Why may not I have a garden too? I have enough land and money for something of the same sort in a smaller way." The old love for flowers and trees, as in boyhood, made the man in middle life determine to plant not so much for himself as for posterity. He had finished a home in the suburbs of St. Louis, Tower Grove, in 1849; and another was in process of building in the city on the corner of Seventh and Locust Streets, when Mr. Shaw returned from Europe in 1851. For five or six years he beautified the grounds of his country home, and in 1857 commissioned Dr. Engelmann, then in Europe, to examine botanical gardens and select proper books for a botanical library. Correspondence was begun with Sir William J. Hooker, the distinguished director of the famous Kew Gardens in London, our own beloved botanist, Professor Asa Gray of Harvard College, and others. Dr. Engelmann urged Mr. Shaw to purchase the large herbarium of the then recently deceased Professor Bernhardi of Erfurt, Germany, which was done, Hooker writing, "The State ought to feel that it owes you much for so much public spirit, and so well directed." March 14, 1859, Mr. Shaw secured from the State Legislature an Act enabling him to convey to trustees seven hundred and sixty acres of land, "in trust, upon a portion thereof to keep up, maintain, and establish a botanic garden for the cultivation and propagation of plants, flowers, fruit and forest trees, and for the dissemination of the knowledge thereof among men, by having a collection thereof easily accessible; and the remaining portion to be used for the purpose of maintaining a perpetual fund for the support and maintenance of said garden, its care and increase, and the museum, library, and instruction connected therewith." For the next twenty-five years Mr. Shaw gave his time and strength to the development of his cherished garden and park. "He lived for them," says Mr. Thomas Dimmock, "and, as far as was practicable, _in_ them; walking or driving every day, when weather and health allowed, and permitting no work of importance to go on without more or less of his personal inspection and direction. The late Dr. Asa Gray, than whom there can be no higher authority, once said, 'This park and the Botanical Garden are the finest institutions of the kind in the country; in variety of foliage the park is unequalled.'"