On December 5, 1955, five days after Montgomery civil rights activist Rose Parks refused to obey the city's policy mandating segregation on buses, black residents launched a bus boycott and elected King as president of the newly-formed Montgomery Improvement Association. As the boycott continued during 1956, King gained national prominence as a result of his exceptional oratorical skills and personal courage. His house was bombed, and he and other boycott leaders were convicted on charges of conspiring to interfere with the bus company's operations. Despite these attempts to suppress the movement, Montgomery's buses were desegregated in December, 1956, after the United States Supreme Court declared Alabama's segregation laws unconstitutional.
In 1957, seeking to build upon the success of the Montgomery boycott movement, King and other Southern black ministers founded the Southern Christian Leadership Conference (SCLC). As the group's president, King emphasized the goal of black voting rights when he spoke at the Lincoln Memorial during the 1957 Prayer Pilgrimage for Freedom. He also traveled to West Africa to attend the independence celebration of Ghana. During 1958, he published his first book, Stride Toward Freedom: The Montgomery Story. The following year, he toured India, increasing his understanding of Ghandi's ideas. At the end of 1959, he resigned from Dexter and returned to Atlanta where the SCLC headquarters were located and where he also could assist his father as pastor of Ebenezer.
Although increasingly portrayed as the preeminent black spokesperson, King was cautious about initiating mass protest activity during the first five years after the Montgomery boycott ended. Instead, southern black college students took the initiative, launched a wave of sit-in protests during the winter and spring of 1960. King sympathized with the student movement, and spoke at the founding meeting of the Student Nonviolent Coordinating Committee (SNCC) in April 1960, although he was at times criticized by SNCC activists determined to assert their independence from older leaders. King's decision in October, 1960, to join a student sit-in in Atlanta led to a sympathetic telephone call to King's wife. Coretta Scott King, from presidential candidate John F. Kennedy. The call helped attract crucial black support to Kennedy's successful campaign. The 1961 "Freedom Rides" which sought to integrate southern transportation facilities, demonstrated that neither King nor Kennedy could control the expanding protest movement spearheaded by students. Conflicts between King and younger militants were also evident when both SCLC and SNCC assisted the Albany (Georgia) Movement's campaign of mass protests during December of 1961 and the summer of 1962.
Although achieving few of his objectives in Albany, King and his staff initiated a major protest campaign in Birmingham, Alabama, where local white police officials were known for their anti-black attitudes. During the spring of 1963, clashes between black demonstrators and police using police dogs and fire hoses generated newspapers headlines throughout the world. In June, President Kennedy, reacting to the Birmingham protests and the obstinacy of segregationist Alabama Governor George Wallace, agreed to submit broad civil rights legislation (which became the Civil Rights Act of 1964) to Congress. Subsequent mass demonstrations in many communities culminated in a march on August 28, 1963 attracting more than 250,000 protesters to Washington, D.C. Addressing the marchers from the steps of the Lincoln Memorial, King delivered his famous "I Have A Dream" oration.
During the year following the march, King's renown as a non-violent leader grew. In 1963, he was named Time magazine's "Man of the Year" and, in December 1964, received the Nobel Peace Prize. Despite fame and accolades, however, King faced strong challenges to his leadership. Malcolm X's (1927-1965) message of self-defense and black nationalism expressed the discontent and anger of northern urban blacks more forcefully than did King's moderation. During the 1965 Selma to Montgomery march which led to the Voting Rights Act of the year. King and his lieutenants had difficulty keeping intra-movement conflicts sufficiently under control. The following year, while participating in a civil rights march through Mississippi, King encountered strong criticism from "Black Power" proponent Stokely Carmichael. Shortly afterward, northern white counter-protesters physically assaulted King during an unsuccessful effort to transfer non-violent protest techniques to the Chicago movement. Despite these leadership conflicts however, King remained committed to the use of non-violent techniques. Early in 1968, he initiated a Poor People's campaign designed to confront economic problems that had not been addressed by early civil rights reforms.
King's ability to achieve his objectives was limited not merely by divisions among blacks, but also by the increasing resistance he encountered from national political leaders. As urban racial violence escalated, FBI Director J. Edgar Hoover intensified his already extensive efforts to undermine King's leadership. King's public criticism of American intervention in the Vietnam war soured his relations with the Lyndon Johnson administration and cost him the support of many white liberals. When he delivered his last speech during a bitter sanitation workers strike in Memphis, he admitted, "We've got some difficult days ahead, but it really doesn't matter with me now, because I've been to the mountaintop." The following evening, April 4, 1968, he was assassinated (James Earl Ray was later convicted of the murder). After his death, King remained a controversial symbol of the African-American civil rights struggle, revered by many for his martyrdom on behalf of non-violence and condemned by others for his militancy and insurgent views. In 1986 King's birthday became a federal holiday.