WASHINGTON -- Bells across the country rang out early Wednesday afternoon to answer a call from one of the most important civil rights speeches in history to "let freedom ring."
Tens of thousands of Americans of all backgrounds and colors thronged to the National Mall in Washington, D.C., to join the nation's first black president and civil rights pioneers in marking the 50th anniversary of Martin Luther King Jr.'s "I Have a Dream" speech.
At precisely 3 p.m., members of the King family tolled a bell to echo King's call 50 years earlier. It was the same bell that once hung in the 16th Street Baptist Church in Birmingham, Ala., before the church was bombed in 1963.
During the rally Wednesday, President Barack Obama challenged new generations to seize the cause of racial equality and honor the "glorious patriots" who marched a half century ago to the very steps from which Rev. Martin Luther King Jr. spoke during the March on Washington.
"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 president's speech was the culmination of a daylong celebration of King's legacy that began with marchers walking 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.
Obama used his address to pay 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. "Their victory great. But we would dishonor those heroes as well to suggest that the work of this nation is somehow complete."
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.
"He talked about his four little children not being judged by the color of their skin but the content of their character," King III told Channel 2's Jovita Moore. "Fifty years after dad's speech, Americans have come together to say that the work is not complete."
Georgia congressman John Lewis, D-Atlanta, the only surviving major speaker from the 1963 march, said we can never forget what others sacrificed to get where we are today.
"Martin Luther ing Jr. taught us the way of peace, the way of love, the way of nonviolence," said Lewis.
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."
One of the themes of many of the speakers Wednesday was connecting with today's youth, getting them involved with civil and humanitarian rights.
Looking out over the sea of people, Channel 2's Dave Huddleston said he could easily see the hundreds of young people in the crowd and many of them said they're ready to pick up the cause.
Renee Sudderth of Stone Mountain said Martin Luther King Jr., Rep. John Lewis and Ambassador Andrew Young were in their 20s and 30s in 1963 when they were in the fight over civil rights. She said it's time for the next generation of young people to pick up the torch and keep the dream alive.
"They've got to keep moving forward. When we're all gone, we have to keep this generation going on, because that's what Martin Luther King dreamed about 50 years ago," said Sudderth.
Lorraine Magee, 20, of Massachusetts, said though King and the others did a lot for equality in our country, everyone has a part and everyone has a role to make the world a better place.
"I'm studying to be an elementary school teacher and I think that's where I'll make the difference, in education, access to knowledge and I think that's where we can make the change and empower people," Magee said.
Jered Crenshaw, 21, of Montgomery, Ala., said young people can empower themselves by standing up for what they believe like King and Lewis did by starting the bus boycotts in his home state of Alabama.
"As youth, we should be advocates and we should work like they did in the '60s and we should be aggressive with youth with a wisdom from our elders," Crenshaw said.
As King's granddaughter rang the bell in Washington, D.C., Atlanta's City Hall joined in on the ceremony, ringing its own bells to commemorate the 50-year anniversary.
City Council President Ceasar Mitchell called it an act of solidarity to honor what King and the march on Washington accomplished.
"Here today, we will let freedom ring. Here today, in Atlanta City Hall, where it couldn't ring in Atlanta City Hall 50 years ago," said city Councilman Michael Bond.
Flowers were laid at the tomb of Martin Luther King Jr. at the King Center in northeast Atlanta. People from around the world visited the center Wednesday, remembering the man who accomplished so much for civil right in the U.S.
Another bell-ringing event was held at Stone Mountain. The park, most well-known for the big carving in tribute to the leaders of the confederacy, was also the birthplace of one of the darkest chapters in the history of America.
When King named the mountaintops from which we should let freedom ring in 1963, one name rang deeper than others: Stone Mountain of Georgia.
Stone Mountain was the birthplace of the 20th-century Ku Klux Klan.
Every year on Labor Day for many decades, thousands of robed and hooded Klan members rallied and burned crosses there.
That history took center stage as speakers went to the mountaintop Wednesday to commemorate King's speech.
"You see, the history of Stone Mountain is deeply rooted in racial intolerance, bigotry and even hate," said Sen. Emanuel Jones, part of the MLK Jr. Advisory Council.
It may be a tribute to progress that we've moved past the chilling chapters toward a brighter promise.
"Fifty years ago, they desired to make a statement to the world that said no more. No more drinking from separate water fountains. No more eating from separate restaurant counters," said Lee May, interim CEO of DeKalb County.
So when the clock struck 3 p.m., bells rang in celebration where once the Klan tried to burn away hope.
Video: WSB-TV Atlanta