London went on to volunteer for the Southern Christian Leadership Conference in the mid-1960s when the civil rights leader moved to Chicago, when black power groups were challenging his notion of peaceful integration.
Historians say the "I Have a Dream Speech" was a turning point in the civil rights movement. Later that year, in November, President John F. Kennedy was assassinated and in 1964, his successor, Lyndon B. Johnson, was able to push through the Civil Rights Act. The law banned segregation in all public venues and ended legal discrimination in employment.
"My parents had been worried about violence," London said. "But the march was so dignified and the speech was the capstone of the day. It provided a different type of aura to the civil rights movement and not just to those like me who were supportive, but a message to the larger society."
Although he later fought for integration of the Boston schools, a turbulent time in one of the North's most liberal cities, London said King's mark is indelible.
"If I had been asked way back in 1963, what it would look like, I could never picture what it looks like today," he said, living in Massachusetts with a black governor and nation with its first black president.
For her part, Lee-Payne is still involved in political activism, fighting against corruption in the city of Detroit, which just recently declared bankruptcy. Her oldest son was killed in a crossfire shooting in 1992 and she now promotes organ donation through a foundation created through his name. She still has the banner that she held: "March on Washington for Jobs and Freedom."
The same photo is on the program of the National Park Service for the 50th anniversary of the event and on the cover of a new book by photographer Scherman, "Eye on the Sixties."
They both plan to return for this week's anniversary.
Scherman got the negatives of his photos of the March last year from the National Archives, which owns the copyrights. Both Lee-Payne and Scherman are now part of a Robert Redford documentary that will be aired Tuesday by PBS, "The March," marking the 50th anniversary.
On April 4, 1968, escaped convict James Earl Ray assassinated King standing on the balcony outside his room at the Motel Lorraine in Memphis. Many say he had predicted his death in his last speech, the day before, "Because I've been to the mountaintop. … And I've seen the promised land. I may not get there with you."
But on the stage at the Lincoln Monument in 1963, those like Lee-Payne, who were riveted by his presence, said, "He was just fearless.'
"As I got older, I realized he was a true man of God," Lee-Payne said. "I had increasingly more respect for him, standing being pulled and yanked by police. … But when you stand up for something, when you fulfill your purpose, you are fearless and you are not afraid of whatever happens.
"What I saw that day was a courageous man with a message from God."