22 November 1964: Malcolm X (1926 - 1965), American Black Muslim leader and founder of the Islamic socialist Organization of Afro-American Unity. (Photo by Express/Express/Getty Images)

Some of the men arrested during the race riot in Rochester, New York State, late July 1964. (Photo by William Lovelace/Express/Getty Images)

US civil rights leader Martin Luther King, Jr. waves to supporters 28 August 1963 from the Lincoln Memorial on the Mall in Washington DC during the 'March on Washington'. On the steps of the Lincoln Memorial, King delivered his 'I Have a Dream' speech, which is credited with mobilizing supporters of desegregation and prompted the 1964 Civil Rights Act. 28 August 2003 marks the 40th anniversay of the speech. King was assassinated on 4 April 1968 in Memphis, Tennessee by James Earl Ray, who confessed to the shooting and was sentenced to 99 years in prison. AFP PHOTO/FILES (Photo credit should read -/AFP/Getty Images)

Police patrol the exterior of a bookshop near the body of dead man lying on the sidewalk in the Watts neighborhood of Los Angeles, circa 1960s. (Photo by Express Newspapers/Getty Images)

Young students picket at youth march for integrated schools rally 25 October 1969 at the Lincoln Memorial in Washington. (photo by National Archive/Newsmakers)