Correspondence, writings and lectures, notes, research materials, student papers, and miscellaneous biographical and genealogical material chiefly relating to the Lynds' sociological research and writings, especially their "Middletown: A Study in Contemporary American Culture" (1929). Other topics include academic and educational affairs at Columbia University and Sarah Lawrence College, national security questions and academic freedom, and the Social Science Research Council. Correspondents include Crane Brinton, Sigmund Diamond, Erik Erikson, Robert K. Merton, David Riesman, and Lynd (Lynn) family members.