Papers document Truesdell's research in rational mechanics and its history, and his role in the development of the field since the late 1940s. Truesdell's education at the California Institute of Technology, Brown and Princeton Universities, and his positions at the Naval Ordnance and Research Laboratories (1946-1951), Indiana University (1950-1961), and the Johns Hopkins University (1961-) are documented. Papers consist largely of drafts of Truesdell's published and unpublished books and articles, and notes on his lectures and courses. Drafts of publications chiefly postdate 1964. Also included are biographical and autobiographical writings and reminiscences by and about Truesdell, together with his student class notes. Included are correspondence, lecture and course notes, lists of publications, grant proposals, reports, reprints, and photographs.