An African-American clergyman and political leader of the twentieth century; the most prominent member of the civil rights movement. King became famous in the 1950s and 1960s through his promotion of nonviolent methods of opposition to segregation, such as boycotts of segregated city buses, or sit-ins at lunch counters that would not serve black people. His “Letter from Birmingham Jail” defended this kind of direct, nonviolent action as a way of forcing people to take notice of injustice. King helped organize the march on Washington in 1963 that drew hundreds of thousands of supporters of civil rights to Washington, D.C., for a mass rally. At this march, he described a possible future of racial harmony in his most famous speech, which had the refrain “I have a dream.” In 1964, he received the Nobel Prize for peace. King was assassinated by James Earl Ray in 1968.