African-American civil rights activist Martin Luther King, Jr. (1929 - 1968, centre) listening to a transistor radio in the front line of the third march from Selma to Montgomery, Alabama, to campaign for proper registration of black voters, 23rd March 1965. Among the other marchers are: Ralph Abernathy (1926 - 1990, second from left), Ralph Bunche (1903 - 1971, third from right) and Rabbi Abraham Joshua Heschel (1907 - 1972, far right). The first march ended in violence when marchers were attacked by police. The second was aborted after a legal injunction was issued.  (Photo by William Lovelace/Daily Express/Hulton Archive/Getty Images)