Associate justice of the United States Supreme Court, chairman of the United States Securities and Exchange Commission, and professor of law. Correspondence, speeches and writings, subject files, Supreme Court files, financial records, family papers and genealogy, printed matter, photographs, and other papers documenting Douglas's legal and judicial career, government service, concern for the environment, and other interests.

Government official and lawyer. Diaries, correspondence, memoranda, notes, speeches and statements, writings, reports, photographs, newspaper clippings, printed matter, and other material documenting Gardner's career as a public official and lawyer in private practice.

United States senators from Montana. Official correspondence, personal correspondence, speeches, legislative files, pamphlets, newspaper clippings, scrapbooks, and photographs relating chiefly to the senatorial career of Walsh and his successor, John Edward Erickson.