Correspondence, memoranda, writings, speeches, transcripts of interviews, reports, notes, subject files, draft and printed legislative bills, briefing books, press releases, photographs, and other papers relating primarily to Brooke's career as attorney general of Massachusetts (1963-1966) and as U.S. senator (1967-1978). Brooke's cases as attorney general pertain to conflict of interest, consumer protection, corruption, eminent domain, and the case against Albert De Salvo, known as the Boston Strangler. His chief interest as senator concerned such domestic issues as housing, the aged, and poverty.

Other topics include the bicentennial of the American Revolution, civil rights, unfair competition, economic conditions in Massachusetts, energy policy, fishing rights, foreign policy, military base closures, military policy, the financial crisis of New York, N.Y., nominations of Clement H. Haynsworth and G. Harrold Carswell to the U.S. Supreme Court, Vietnam war, and the Watergate scandal. Includes materials relating to Brooke's participation in Republican party politics; papers (1979-1988) from his private legal practice in Washington, D.C., relating primarily to cases involving the National Association for the Advancement of Colored People; and files of from the Massachusetts assistant attorney generals office.

Correspondents include Howard H. Baker, John S. Bottomly, Jimmy Carter, Silvio O. Conte, Clarence Elam, Gerald R. Ford, Albert A. Gammal, Mark O. Hatfield, Hubert H. Humphrey, Jacob K. Javits, Lyndon B. Johnson, Kivie Kaplan, Edward T. Martin, Richard M. Nixon, Glendora M. Putnam, Harold Putnam, Nelson A. Rockefeller, Francis W. Sargent, Hugh Scott, Josiah A. Spaulding, John A. Volpe, Roger Woodworth, and Charlotte Yaffee.