GWEN IFILL: Now to the highlights of a remarkable day in Washington.
Ray Suarez has that story.
RAY SUAREZ: It was August 28, 1963, and more than 200,000 people gathered on the National Mall and listened raptly to Dr. Martin Luther King's historic appeal.
MARTIN LUTHER KING JR., civil rights leader: Because I have a dream today.
(CHEERING AND APPLAUSE)
RAY SUAREZ: Today, thousands gathered again at the Lincoln Memorial, standing for hours through a light rain to commemorate the anniversary. The atmosphere and music were at times festive and at times solemn, as with a rendition of "Blowin' in the Wind" that included the parents of slain Florida teenager Trayvon Martin.
RAY SUAREZ: Scores of speakers honored King's legacy and sought to expand it to new groups and new times.
Democratic Congressman Joaquin Castro of Texas said Latinos, too, look to the struggles of black Americans as a model.
REP. JOAQUIN CASTRO, D-Tex.: As somebody of a younger generation of Americans, I want to promise you that all of the struggles and all of the fights and all of the work and all of the years that you put in to making our country a better place, to helping our leaders understand that freedom and democracy are prerequisites to opportunity, I want you to know that this generation of Americans will not let that dream go.
RAY SUAREZ: Women played a key role in organizing the original march, though none were featured speakers. Today's program included a number of women. Activist and journalist Myrlie Evers-Williams, the wife of assassinated civil rights activist Medgar Evers emphasized unity of purpose.
MYRLIE EVERS-WILLIAMS, civil rights leader: The movement can no longer afford an individual approach to justice. Ours is an interconnected struggle, black, white, male, female, young, old, everyone. We are all entitled to and protected by this country that we call home.
RAY SUAREZ: President John F. Kennedy's daughter, Caroline, called for today's Americans to build on their parents achievements. Her father was president at the time of the 1963 march.
CAROLINE KENNEDY, daughter of President John F. Kennedy: Fifty years ago, our parents and grandparents marched for jobs and freedom. We have suffered and sacrificed too much to let their dream become a memory.
RAY SUAREZ: Dr. King's daughter, the Reverend Bernice King, was an infant in 1963. Today, she spoke as head of the King Center for Nonviolent Social Change.
REV. BERNICE KING, daughter of Martin Luther King Jr.: For there's a remnant from 1963, Congressman Lewis, Ambassador Young, that still remains, who has come to bequeath that message of freedom to a new generation of people who must now carry that message in their time, in their communities, amongst their tribes, and amongst their nations of the world.
RAY SUAREZ: Georgia Congressman John Lewis was the youngest person to address the crowd in 1963. He's now 73 years old and the only living speaker from that day. He reflected on the changes he's seen.
REP. JOHN LEWIS, D-Ga.: Fifty years later, we can ride anywhere we want to ride. We can stay where we want to stay. Those signs that said white and colored are gone.
But there are still invisible signs, barriers in the hearts of humankind that form a gulf between us. Too many of us still believe our differences define us, instead of the divine spark that runs through all of human creation.
RAY SUAREZ: Another Georgian, former President Jimmy Carter, warned of new barriers in the forms of assaults on voting rights.
JIMMY CARTER, former president of the United States: I believe we all know how Dr. King would have reacted to new the I.D. requirements to exclude certain voters, especially African-Americans.
I think we all know how Dr. King would have reacted to the Supreme Court striking down a crucial part of the voters rights act just recently passed overwhelmingly by Congress.
RAY SUAREZ: Former President Bill Clinton urged Americans to put aside political and racial divisions as they look to the future.
BILL CLINTON, former President of the United States: The choice remains as it was on that distant summer day 50 years ago, cooperate and thrive, or fight with each other and fall behind.
We should all thank God for Dr. King and John Lewis and all those who gave us a dream to guide us, a dream they paid for, like our founders, with their lives, their fortunes, their sacred honor. And we thank them for reminding us that America is always becoming, always on a journey. And we all, every single citizen among us, have to run our lap.
RAY SUAREZ: A third former president, George W. Bush, was unable to attend today, as he recovers from a recent heart procedure. Instead, he issued a statement saying: "There's still a need for every American to help hasten the day when Dr. King's vision is made real in every community, when what truly matters is not the color of a person's skin, but the content of their character."
The moment that Dr. King delivered his famous address 50 years ago, with the appeal to let freedom ring, was marked by a bell-ringing ceremony. That set the stage for the first African-American president, who said the struggle for economic opportunity remains the nation's great unfinished business, but he voiced hope.
PRESIDENT BARACK OBAMA: There's a reason why so many who marched that day and in the days to come were young, for the young are unconstrained by habits of fear, unconstrained by the conventions of what is.
They dared to dream differently, to imagine something better. And I am convinced that same imagination, the same hunger of purpose stirs in this generation. We might not face the same dangers of 1963, but the fierce urgency of now remains. We may never duplicate the swelling crowds and dazzling procession of that day so long ago. No one can match King's brilliance, but the same flame that lit the heart of all who are willing to take a first step for justice, I know that flame remains.
RAY SUAREZ: The president called for Americans of all backgrounds to take up that flame, instead of waiting for the national government to lead the way.
BARACK OBAMA: Everyone who realizes what those glorious patriots knew on that day, that change does not come from Washington, but to Washington, that change has always been built on our willingness, we, the people, to take on the mantle of citizenship, you are marching.
(CHEERING AND APPLAUSE)
BARACK OBAMA: And that's the lesson of our past. That's the promise of tomorrow, that in the face of impossible odds, people who love their country can change it.
And when millions of Americans of every race and every region, every faith and every station can join together in a spirit of brotherhood, then those mountains will be made low and those rough places will be made plain, and those crooked places, they straighten out towards grace, and we will vindicate the faith of those who sacrificed so much, and live up to the true meaning of our creed, as one nation under God, indivisible, with liberty and justice for all.
(CHEERING AND APPLAUSE)
RAY SUAREZ: The sound of bells reached far beyond Washington as well today. Nationwide, there were ceremonies at more than 300 churches, schools and historical sites. Commemorations were also held around the world.