Dr. Martin Luther King, Jr. rides in the back seat of a police car with a police dog as he is returned to jail in St. Augustine, Fla., after testifying before a grand jury investigating racial unrest in the city, June 12, 1964. Andrew Young is seen outside the car. (AP Photo)

The Rev. Dr. Martin Luther King Jr. is accompanied by his wife, Coretta Scott King, as he appears at a press conference on the occasion of the release of his book

The Rev. Martin Luther King, Jr., left, of the Southern Christian Leadership Conference, and Malcolm X, head of a new group known as Muslim Mosque, Inc., smile for photographers March 26, 1964, at the Capitol. They shook hands after King announced plans for

The Rev. Martin Luther King of the Southern Christian Leadership Conference, holds news conference today March 26, 1964 at the capital (AP Photo/Henry Griffin)

Dr. Martin Luther King, Jr. is shown discussing a forthcoming speech, March 18, 1964, from his home in Atlanta, Ga. Dr. King said that he had stepped up demonstrations in the south during the summer. (AP Photo)

Civil rights leader Dr. Martin Luther King, Jr., center, receives the 1963 St. Francis' Peace Medal from the Lay Organization of Franciscans, a Roman Catholic organization, Nov. 9, 1963, in New York. From left, Rev. Philip Marquard, making the presentation, King, and Rev. John LaFarge. (AP Photo)

Civil rights leader Rev. Dr. Martin Luther King Jr. is followed by Rev. Fred Shuttlesworth, left, and Ralph Abernathy as they attend funeral services at the Sixth Avenue Baptist Church for three of the four black girls killed in a church explosion in Birmingham, Ala., Sept. 18, 1963. (AP Photo)

PHOTO: EAST NEWS/AFP The civil rights leader Martin Luther King (C) waves to supporters 28 August 1963 on the Mall in Washington DC (Washington Monument in background) during the "March on Washington". King said the march was "the greatest demonstration of freedom in the history of the United States." Martin Luther King was assassinated on 04 April 1968 in Memphis, Tennessee. James Earl Ray confessed to shooting King and was sentenced to 99 years in prison. King's killing sent shock waves through American society at the time, and is still regarded as a landmark event in recent US history.

The crowds seen at the march on Washington, D.C. in which Dr. Martin Luther King gave his eloquent

Dr. Martin Luther King Jr., center with arms raised, marches along Constitution Avenue with other civil rights protestors carrying placards as they walked from the Washington Monument to the Lincoln Memorial for the March on Washington, August 28, 1963. (AP Photo)

Dr. Martin Luther King Jr., head of the Southern Christian Leadership Conference, addresses marchers during his

Rev. Martin Luther King Jr., president of the Southern Christian Leadership Conference, right, and Roy Wilkins of the NAACP, are seen, Aug. 1963. (AP Photo)

Aug 12, 1963 - Washington, DC, USA - Dr. MARTIN LUTHER KING pictured shaking hands during 'The March on Washington for Jobs and Freedom.' Martin Luther King, Jr. was the most famous leader of the American civil rights movement, a political activist, who became in 1964 the youngest man to be awarded the Nobel Peace Prize (for his work as a peacemaker, promoting nonviolence and equal treatment for different races). On April 4, 1968, Dr. King was assassinated in Memphis, Tennessee. In 1977, he was posthumously awarded the Presidential Medal of Freedom by Jimmy Carter. In 1986, Martin Luther King Day was established as a United States holiday. (Credit Image: ? KEYSTONE Pictures USA)/ eyevine

The Rev. Dr. Martin Luther King Jr., head of the Southern Christian Leadership Conference, gestures during his

Six leaders of the nation's largest black civil rights organizations meet in New York's Hotel Roosevelt on July 2, 1963, to plan a civil rights march on Washington. From left, are: John Lewis, chairman Student Non-Violence Coordinating Committee; Whitney Young national director, Urban League; A. Philip Randolph, president of the Negro American Labor Council; Dr. Martin Luther King Jr. president Southern Christian Leadership Conference; James Farmer, Congress of Racial Equality director; and Roy Wilkins, executive secretary, National Association for the Advancement of Colored People. (AP Photo/Harry Harris)

The Rev. Dr. Martin Luther King is shown during appearance on the

Civil rights leaders, Rev. Martin Luther King Jr., left, Rev. Fred Shuttlesworth, center, and Rev. Ralph Abernathy hold a news conference in Birmingham, Al., on May 8, 1963. They are suspending racial demonstrations and King said a settlement is near. (AP Photo)

The Rev. Martin Luther King Jr., right, and his close associate, Rev. Ralph Abernathy, are released after 8 days from a jail in Birmingham, Ala., on April 20, 1963. (AP Photo)

A police officer holds the Rev. Martin Luther King Jr. by his belt as he leads him to the paddy wagon, following arrest at an anti-segregation protest in downtown Birmingham, Ala., on April 13, 1963. An unidentified cameraman is documenting the scene. (AP Photo)

Rev. Ralph Abernathy, left, and Rev. Martin Luther King Jr. lead a column of demonstrators as they attempt to march on Birmingham, Ala., city hall April 12, 1963. Police intercepted the group short of their goal. (AP Photo/Horace Cort)