Papers of the American painter, art critic. Correspondence, 1910-1969; holograph and typescript essays, lectures, and speeches; photographs; and printed material, including articles, exhibition catalogs, and material relating to the National Academy of Design, of which Clark wrote a history.

Correspondence (1917-1965); artwork, including lithographic plates and sketches; photographs and reproductions of paintings; and printed material, including clippings (1928-1965), exhibition catalogs (1927-1965), and reviews. Correspondents include Bill Alexander, the American Artists Group, Inc., Erwin S. Barrie, Ray Bethers, George Biddle, Julius Bloch, Mortimer Borne, W. Sterry Branning, Lucile E. Bush, Millicent Carey, the Carnegie Institute, the Chesapeake and Ohio Railway Compnay, Van Cort, Russell Cowles, Katharine Day, Dorothy Dehner, Juliana Force, Kathryn Gamble, Daisy Gill, Lloyd Goodrich, Buckner Hollingsworth, Kaj Klitgaard, Yasuo Kuniyoshi, Archibald MacLeish, Hughes Mearns, Hermon More, Hobson Pittman, Frances M. Pollak, Henry Varnum Poor, Homer Saint-Gaudens, Silvia Saunders, Jean Paul Slusser, Charles A. Smart, Carl Spaatz, Eugene Speicher, Francis H. Taylor, Zoraida E. Weeks, and William Zorach.

Papers of the American painter, illustrator, cartoonist, lithographer. Correspondence (1927-1950); original drawings, paintings, and prose by Gropper and others; published material, including cartoons from New Masses, clippings, exhibition lists, and illustrations (1918-1968); and a scrapbook containing birthday congratulations.