Sportswriter, baseball executive, and author. Correspondence, drafts of books and articles, notes, memoranda, newspaper clippings, and printed matter relating primarily to Mann's biography of Branch Rickey and to Rickey's contributions to professional baseball.

Major league baseball manager and executive. Correspondence, family papers, speeches and writings, memoranda, scouting and other reports, notes, subject files, scrapbooks, photographs, and other papers, chiefly from 1936 to 1965, documenting Branch Rickey's career.