Papers of the American philanthropist, poet. Correspondence; secretarial daybooks, 1922-1957; manuscripts; legal and financial papers. Organizational correspondence includes that of the Academy of American Poets, American Academy of Arts and Letters, American Geographical Society, American Museum of Natural History, American Numismatic Society, Brookgreen Gardens, California Palace of the Legion of Honor, Hispanic Society of America, Mariners' Museum, Metropolitan Museum of Art, Museum of the American Indian, National Academy of Design, National Arts Club, National Sculpture Society, New-York Historical Society, New York Zoological Society, and Yale University.