Part I consists chiefly of case files comprised of opinion and administrative files from Brennan's service on the Supreme Court together with dockets (1956-1975) and miscellaneous papers. The opinion files pertain to such issues as freedom of speech and association, sex discrimination, procedural due process, privacy, affirmative action, legislative apportionment, labor laws, obscenity, and unreasonable search and seizure and reflect Brennan's championship of the rights of the indigent and his opposition to the death penalty. Correspondents include Hugo LaFayette Black, William O. Douglas, Arthur J. Goldberg, Thurgood Marshall, Earl Warren, and other members of the court during Brennan's tenure.

Part II is comprised of correspondence files spanning Brennan's Supreme Court career and his years in retirement, supplemental case files consisting of opinion and administrative files, case histories, speeches and writings, and other papers. Includes material relating to capital punishment and obscenity cases. Correspondents include David L. Bazelon, Edmond Nathaniel Cahn, Daniel Crystal, Alfred Di Lascia, George C. Edwards, Morris Leopold Ernst, Robert C. Finley, Arthur J. Freund, Paul Abraham Freund, Frank T. Gallagher, Donald Barnett King, Alfred A. Knopf, Anthony Lewis, Daniel P. Moynihan, Walter F. Murphy, Joseph O'Meara, John W. Oliver, Louis H. Pollak, Curtis R. Reitz, Walter V. Schaefer, Bernard Schwartz, Bernard G. Segal, Arthur T. Vanderbilt, Francis L. Van Dusen, Brian Walsh, Stanley A. Weigel, Charles Alan Wright, and J. Skelly Wright. Other correspondents include federal and state judges, law professors, attorneys in private practice, and law clerks.