50th anniversary of Martin Luther King Jr.'s 'I have a dream' speech

Marchers gathered in Washington on Aug. 24, 2013, to celebrate the 50th anniversary of  Martin Luther King, Jr.'s famous "I Have a Dream" speech on Aug. 28, 1963.  The civil rights pioneer is seen here speaking from the podium that day at the March on Washington.  (Library of Congress)

King was born on Jan. 15, 1929, in Atlanta, Ga.  He began his career as a Baptist minister and became a civil-rights activist early on, leading the Montgomery, Ala., Bus Boycott in 1955 and helping found the Southern Christian Leadership Conference (SCLC) in 1957.  (Library of Congress)

"I have a dream that one day this nation will rise up and live out the true meaning of its creed: We hold these truths to be self-evident that all men are created equal," King said during his famous speech. "I have a dream that one day on the red hills of Georgia the sons of former slaves and the sons of former slave owners will be able to sit down together at the table of brotherhood." (Library of Congress)

Despite a growing number of supporters, King still struggled making his dream a reality.  King is seen here in 1963 being seized by a police officer and led to a police wagon, after an anti-segregation march in Birmingham, Ala.  (Library of Congress)

Martin Luther King and Malcolm X waiting to speak at a press conference on March 26, 1964.  (Library of Congress)

King traveled the country delivering his message. He is seen here addressing a group of Watts residents following the summer riots of 1965.  (Library of Congress)

King was assassinated outside his hotel room at the Lorraine Motel in Memphis, Tenn., on April 4, 1968 by drifter and former convict James Earl Ray. Ray was apprehended after a two-month search and pleaded guilty in 1969.  He was sentenced to 99 years and died in prison on April 23, 1998.  The Lorraine Motel is now part of the National Civil Rights Museum. It is seen here in this image from 2008.  (Reuters)

King's murder sparked riots and demonstrations in cities across the country. In this image, demonstrators stand with signs, one reading "Let not his death be in vain", in front of the White House in April 1968.  (Library of Congress)

This image shows ruins of a store that was destroyed in one of the April 1968 riots in Washington, D.C. following King's assassination. (Library of Congress)

The Martin Luther King Jr. memorial was dedicated on the National Mall in Washington, D.C. on Oct. 16, 2011. (Reuters )

Oct. 16, 2011: U.S. President Barack Obama walks with his family at the dedication ceremony of the Martin Luther King, Jr. Memorial in West Potomac Park in Washington. The memorial's website describes it as King "captured in a moment of reflective thought." It was sculpted by artist Master Lei Yixin and serves as the forward element of the Stone of Hope. (Reuters)

50 years later, marchers honor King, gathering along the reflecting pool on Aug. 24, 2013, on the National Mall during the anniversary of the 1963 March on Washington for Jobs and Freedom at the Lincoln Memorial. (Reuters)

Aug. 24, 2013: Demonstrators march during the 50th anniversary of the 1963 March on Washington for Jobs and Freedom at the Lincoln Memorial in Washington. (Reuters)

Martin Luther King III remembers his father at the ceremony at the Lincoln Memorial honoring the 50th anniversary of the 1963 March on Washington on Aug. 24, 2013. (Reuters)

Aug. 24, 2013: Marchers hold signs during the 50th anniversary of the 1963 March on Washington for Jobs and Freedom at the Lincoln Memorial in Washington. (Reuters)

"I have a dream that one day every valley shall be exalted, every hill and mountain shall be made low, the rough places will be made plain, and the crooked places will be made straight, and the glory of the Lord shall be revealed, and all flesh shall see it together." (Reuters)