WASHINGTON - For many among the tens of thousands of Americans who thronged to the National Mall to mark the 50th anniversary of the March on Washington, President Barack Obama's challenge to seize the cause of racial equality from the "glorious patriots" of the tumultuous 1960s struck a deep generational chord.
Standing on hallowed ground for the civil rights movement, the very steps on the Lincoln Memorial from which the Rev. Martin Luther King Jr. spoke a half-century ago, Obama urged each person in the crowd Wednesday to become a modern-day marcher for racial harmony and economic justice.
"The arc of the moral universe may bend toward justice but it doesn't bend on its own," Obama said in an allusion to King's own message.
The nation's first black president and civil rights pioneers joined the crowd under showery skies 50 years to the day that King, with soaring oratory and a steely countenance, delivered his "I Have a Dream" speech, pleading for Americans to unite and create a land of opportunity for all.
Obama's words were steeped in history and rich with symbolism, especially for those in the crowd who could count parents or other family members who were part of the movement five decades ago.
Obama paid tribute to the marchers of 1963 and that era - the maids, laborers, students and more who came from ordinary ranks to engage "on the battlefield of justice" - and he implored Americans not to dismiss what they accomplished.
"To dismiss the magnitude of this progress, to suggest - as some sometimes do - that little has changed, that dishonors the courage, the sacrifice, of those who paid the price to march in those years," Obama said to a crowd that jammed around the Reflecting Pool, which stretches from the Lincoln Memorial to the World War II Memorial.
It was at her mother's urging that Micole Jameson, 38, made the 10-hour drive from Detroit with her husband and their two children to commemorate the historic moment. Jameson's mother, Carol Jance, is white, and her father, Michael Sanford, was black.
"She said it was because of King that they were able to have a relationship and have me," said Jameson, who sat in a wheelchair adorned with a sign made from an old family photo and the words "Product of the Dream" on one side, and "I am the Dream" on the other.
Jameson said she would return home inspired by the experience. "We need our own movement," she said of her generation.
White and black and of other races and ethnicities, they all 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.
Jesse N. Holmes, 56, of Washington, wore a signboard around his neck with a photo, which had appeared in Ebony magazine, of his father participating in the 1963 march. "My father was here 50 years ago. I'm following in his footsteps," his sign read.
Obama's speech was the culmination of daylong celebration that began with marchers walking the streets of Washington behind a replica of the Montgomery, Ala., bus on which Rosa Parks in 1955 refused to give up her seat to a white man.
At precisely 3 p.m., members of the King family tolled a bell to echo King's call 50 years earlier to "let freedom ring." It was the same bell that once hung in the 16th Street Baptist Church in Birmingham, Ala., where four black girls were killed when a bomb planted by a white supremacist exploded in 1963.
Georgia Rep. John Lewis, a former freedom rider and the sole survivor of the main organizers of the 1963 march, recounted the civil rights struggles of his youth and exhorted Americans to "keep the faith and keep our eyes on the prize."
Two of the four living former presidents, Bill Clinton and Jimmy Carter, spoke of King's legacy - and of problems still to overcome.
"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."
"In truth, he helped to free all people," Carter said of King. 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 unemployment among blacks.
Former President George W. Bush didn't attend, a spokesman said, because he was recovering from a recent heart procedure. Bush said in a statement that Obama's presidency reflects "the promise of America" and "will help us honor the man who inspired millions to redeem that promise."
House Speaker John Boehner, R-Ohio, and Majority Leader Eric Cantor, R-Va., were invited to speak but declined, aides said. Boehner had participated along with other congressional leaders at a July 31 event marking the anniversary of the march before Congress began a five-week summer recess. Cantor joined Lewis, the Georgia congressman, earlier this year in Selma, Ala., to honor King's legacy.
Organizers of the rally broadened the focus well beyond racial issues, with speakers addressing 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."
Associated Press writers Darlene Superville, Eric Tucker and Brett Zongker contributed to this report.