WASHINGTON (AP) — Taking stock of progress made and still to come, Americans of all backgrounds and colors massed on the National Mall on Wednesday to hear President Barack Obama and civil rights pioneers commemorate Dr. Martin Luther King's "I Have a Dream" speech on the same spot where he gave unforgettable voice to the struggle for racial equality 50 years earlier.
It was a moment rich with history and symbolism: the first black president standing where King first sketched his dream.
Marchers walked the streets of Washington behind a replica of the transit bus that Rosa Parks once rode when she refused to give up her seat to a white man. Midafternoon, the same bell was to ring that once hung in the 16th Street Baptist Church in Birmingham, Ala., before the church was bombed in 1963.
Two former presidents, Bill Clinton and Jimmy Carter, spoke movingly of King's legacy — and of problems still to overcome — as Obama listened.
"This march, and that speech, changed America," Clinton declared, remembering the impact on the world and himself as a young man. "They opened minds, they melted hearts and they moved millions — including a 17-year-old boy watching alone in his home in Arkansas."
Carter said King's efforts had helped not just black Americans, but "In truth, he helped to free all people."
Still, Carter listed a string of current events that he said would have spurred King to action in this day, including the proliferation of guns and stand-your-ground laws, a Supreme Court ruling striking down parts of the Voting Rights Act, and high rates of joblessness among blacks.
Oprah Winfrey, leading the celebrity contingent, recalled watching the march as a 9-year-old girl and wishing she could be there to see a young man who "was able to force an entire country to wake up, to look at itself and to eventually change."
"It's an opportunity today to recall where we once were in this nation," she said.
Setting an energetic tone for the day, civil rights veteran Andrew Young, a former U.N. ambassador and congressman, sang an anthem of the civil rights movement and urged the crowd to join in as he belted out: "I woke up this morning with my mind stayed on freedom." He ended his remarks by urging the crowd to "fight on."
Civil rights activist Myrlie Evers-Williams, whose husband Medgar Evers was murdered in 1963, said that while the country "has certainly taken a turn backwards" on civil rights she was energized to move ahead and exhorted others to step forward as well.
Tens of thousands assembled in soggy weather at the Lincoln Memorial, where King, with soaring, rhythmic oratory and a steely countenance, had pleaded with Americans to come together to stomp out racism and create a land of opportunity for all.
White and black, they came this time to recall history — and live it.
"My parents did their fair share and I feel like we have to keep the fight alive," said Frantz Walker, a honey salesman from Baltimore who is black. "This is hands-on history."
Kevin Keefe, a Navy lawyer who is white, said he still tears up when he hears King's speech.
"What happened 50 years ago was huge," he said, adding that there's still progress to be made on economic inequality and other problems.
King's eldest son, Martin Luther King III, just 5 when his father spoke at the Mall, spoke of a dream "not yet realized" in full.
"We've got a lot of work to do but none of us should be any ways tired," he said. "Why? Because we've come much too far from where we started."
Organizers of the rally broadened the focus well beyond racial issues, bringing speakers forward to address the environment, gay rights, the challenges facing the disabled and more. The performers, too, were an eclectic crowd, ranging from Maori haka dancers to LeAnn Rimes singing "Amazing Grace."
Jamie Foxx tried to fire up a new generation of performers and ordinary "young folks" by drawing on the example of Harry Belafonte, who stood with King 50 years ago.
"It's time for us to stand up now and renew this dream," Foxx declared.
Forest Whitaker told the crowd it was their "moment to join those silent heroes of the past."
"You now have the responsibility to carry the torch."
NBA legend Bill Russell told the crowd he'd been at the 1963 march as an "interested bystander," and quipped with a smile, "It's nice to be anywhere 50 years later."
Turning serious, he added: "You only register progress by how far you have to go.... The fight has just begun and we can never accept the status quo until the word 'progress' is taken out of our vocabulary."
Slate gray skies gave way to sunshine briefly peeking from the clouds as the "Let Freedom Ring" commemoration unfolded. After that, a steady rain.
Among faces in the crowd: lawyer Ollie Cantos of Arlington, Va., there with his 14-year-old triplets Leo, Nick and Steven. All four are blind, and they moved through the crowd with their hands on each other's shoulders, in a makeshift train.
Cantos, who is Filipino, said he brought his sons to help teach them the continuing fight for civil rights.
"The disability rights movement that I'm a part of, that I dedicate my life to, is actually an extension of the original civil rights movement," said Cantos. "I wanted to do everything I can to school the boys in the ways of the civil rights movement and not just generally but how it effects them personally."
D.C. plumber Jerome Williams, whose family tree includes North Carolina sharecroppers, took the day off work to come with his wife and two kids. "It's a history lesson that they can take with them for the rest of their lives," he said.
It seemed to work. His son Jalen, marking his 17th birthday, said: "I'm learning the history and the stories from my dad. I do appreciate what I do have now."
Performers included Peter Yarrow and Noel Paul Stookey, their voices thinner now than when they performed at the original march as part of the folk trio Peter, Paul and Mary. They sang "Blowin' in the Wind," as the parents of slain black teenager Trayvon Martin joined them on stage and sang along. The third member of the trio, Mary Travers, died in 2009.
The scheduled appearance later Wednesday of Obama was certain to embody the fulfilled dreams of hundreds of thousands who rallied there in 1963. Obama has not often talked publicly about racial issues in the time he has been president. He did, however, talk at some length about the challenges he faced as a young black male as he discussed the case of Martin, the Florida teen-ager killed in a confrontation with neighborhood watch volunteer George Zimmerman.
Also joining the day's events were Lynda Bird Johnson Robb, daughter of Lyndon Johnson, the president who signed the 1964 Civil Rights Act and the 1965 Voting Rights Act, and Caroline Kennedy, daughter of John F. Kennedy.
Obama considers the 1963 march a "seminal event" and part of his generation's "formative memory." A half-century after the march, he said, is a good time to reflect on how far the country has come and how far it still has to go.
In an interview Tuesday on Tom Joyner's radio show, Obama said he imagines that King "would be amazed in many ways about the progress that we've made" but he also took note of work yet to do.
"When it comes to the economy, when it comes to inequality, when it comes to wealth, when it comes to the challenges that inner cities experience, he would say that we have not made as much progress as the civil and social progress that we've made," the president said.
Bush, in a statement, said Obama's presidency is a story that reflects "the promise of America" and "will help us honor the man who inspired millions to redeem that promise." A spokesman said the former president declined to attend because he was recovering from a recent heart procedure.
Associated Press writers Darlene Superville, Brett Zongker and Andrew Miga contributed to this report.