U.S. Rep. Barbara Jordan (D-Texas) on the House Judiciary Committee during a hearing on the impeachment of President Richard Nixon, July 1974. Her primetime remarks on the Constitution riveted the nation and underscored the grave role of serving as a check on the executive branch. Photo: Keystone/Hulton Archive/Getty Images

Students sit on a bus from Columbia Point to Roxbury High School on Sept. 13, 1974, the second day of school under the new busing system to desegregate Boston Public Schools. The system was met with solid resistance and violence from many residents of Boston's neighborhoods. Photo: William C. Curtis/The Boston Globe via Getty Images

Muhammad Ali stands over George Foreman during a dramatic 8th-round knockout to regain the heavyweight title in Zaire, known as the "Rumble in the Jungle." It was one of the most-watched televised events at the time. Photo: Tony Triolo /Sports Illustrated via Getty Images

School children with placards reading 'No More Police Harassment' during a school strike in London, in April 1974. They are demanding the release of the Brockwell Three, three young Black men who were arrested during a disturbance in Brockwell Park, South London, and sentenced to three years in prison. Photo: Evening Standard/Hulton Archive/Getty Images

American actor Rodney Grier and his sister, American actress and singer Pam Grier, attend the 7th NAACP Image Awards, held at the Hollywood Palladium in Los Angeles in January 1974. Photo: Frank Edwards/Fotos International/Archive Photos/Getty Images

United Farm Workers leader Cesar Chavez is given the Martin Luther King Nonviolent Peace Award at a rally in Atlanta in January 1974. Coretta Scott King, widow of the late Dr. King, made the presentation. The affair opened the two-day celebration of King's birthday. Photo: Bettmann / Contributor

Black Panther and writer Eldridge Cleaver and his wife, Kathleen, sit in their apartment in Paris during their exile in 1974. Photo: Nik Wheeler/Corbis via Getty Images

Two men posing on a street on the South Side of Chicago, May 1974. Photo: John White/U.S. National Archives via Smith Collection/Gado/Getty Images