Correspondence, memoranda, reports, newsletters, and other papers relating to Rosenblatt's career as a lobbyist chiefly while working with the National Committee for an Effective Congress (NCEC) to curb the power and influence of Joseph McCarthy in his efforts opposing communism. Also includes papers relating to the establishment of the McCarthy Clearing House, the Democratic Study Group, and the Foreign Policy Clearing House, and to congressional elections and financial support for congressional candidates. Individuals represented include George E. Agree, Jack Anderson, William Benton, Kenneth Milton Birkhead, Ralph E. Flanders, John Howe, Ronald W. May, Robert R. Nathan, Lucille Lang Olshine, Drew Pearson, and Gerhard P. Van Arkel.

Also includes material concerning Rosenblatt's work with National Counsel Associates, the Draft Stevenson movement in the 1960 presidential election, Coordinating Committee for Democratic Action, N.Y., the American League for a Free Palestine, and the establishment of Israel. Includes recollections of Hillel Kook (Peter Bergson) and Harry Louis Selden.

Part II consists of correspondence, family papers, papers of Maurice Rosenblatt's brother Frank, a National Committee for an Effective Congress series, subject files, and a miscellany file of writings, memorabilia, and photographs. Subjects include Rosenblatt's student years at the University of Wisconsin, Madison, Wis., his World War II military service especially in New Guinea, and Israel. Correspondents include Laura Barone, Bernice Rosenblatt, Frank Rosenblatt, and Katherine Rosenblatt.