The nation has made progress toward the dream of racial equality envisioned by Dr. Martin Luther King Jr., President Barack Obama told tens of thousands on the National Mall on Wednesday, but creating economic opportunity for millions of Americans remains "our great unfinished business."
In an address that drew on themes of unity reminiscent of his 2008 campaign, the nation's first black president said continuing King's legacy would require policymakers to resist state ballot access laws, increase opportunities for education and confront a gap in wealth between the races that has grown more pronounced in recent decades.
"The arc of the moral universe may bend towards justice, but it doesn't bend on its own," Obama said from the steps of the Lincoln Memorial, where King delivered his "I have a dream" speech 50 years earlier. "To secure the gains this country has made requires constant vigilance, not complacency."
Thousands stood in the rain to hear Obama, former Presidents Bill Clinton and Jimmy Carter and members of the King family as they reflected on the 1963 March on Washington and the speech that helped lead to the passage of the Civil Rights Act and the Voting Rights Act.
"Because they kept marching, America changed," Obama said. "Because they marched, America became more free and more fair. … America changed for you and for me. And the entire world drew strength from that example."
The crowd for the event was smaller than the 1963 gathering, and also smaller than a march on Washington Saturday organized by a coalition of civil rights groups.
On Wednesday, people lined up along most of the length of the reflecting pool and included young and old, black and white, and people who participated in the 1963 march.
In addition to the three former presidents, marchers heard from union leaders, actors including Oprah Winfrey, Maryland Gov. Martin O'Malley and Rep. John Lewis of Georgia, the only surviving speaker from the 1963 march.
Speakers stood in front of a massive iron bell, salvaged from the ruins of the bombed-out 16th St. Baptist Church in Birmingham, Ala., where the deaths of four black girls in 1963 would prove another turning point in the civil rights movement.
At the Lincoln Memorial 50 years ago, King exhorted the nation to "Let freedom ring!" Around 3 p.m. Wednesday, the time King delivered the "I have a dream" speech, members of his family rang the bell in a solemn moment to honor the assassinated leader.
Several speakers noted that King's speech and leadership were being remembered at a time when racial tensions have been stoked by last year's fatal shooting of a black teenager in Florida, Trayvon Martin, and a Supreme Court decision in June that struck down a provision of the 1965 Voting Rights Act.
Unemployment among blacks, meanwhile, remains nearly double that of whites — a gap that has not changed significantly since the 1960s. African-American unemployment stood at 12.6 percent last month, compared with 6.6 percent for whites.
Elected officials — all Democrats — and civil rights leaders also used the occasion to tie King's message to a wider range of modern domestic policy issues, including immigration, gay marriage and the minimum wage.
Former President Bill Clinton said Americans should oppose efforts to repeal Obama's health care law and should support federal gun control measures. "A great democracy does not make it harder to vote than to buy an assault weapon," he said.
O'Malley touched on gun control, education, gay marriage, the minimum wage, the death penalty and other issues in remarks that lasted about two minutes.
O'Malley, who has said he is considering a run for president in 2016, said Wednesday's march should prompt a call to action rather than a sense of nostalgia.
"Let there be no comfort in our country for the bigotry of cold indifference," O'Malley said. "For there are still too many lives in America taken from us by violence … too much apathy when the lives of people of color are too often valued less than the lives of white people."
The Republican politicians invited to the event passed on the high-profile platform to promote their vision of the new civil rights landscape. House Speaker John Boehner of Ohio chose to speak at a congressional ceremony last month instead. House Majority Leader Eric Cantor of Virginia had previously scheduled events in North Dakota and Ohio, an aide said.
Former Presidents George H.W. Bush and George W. Bush both could not attend for health reasons, their spokesmen said. The elder Bush, who at 89 years old often uses a wheelchair, rarely attends public events. His son recently underwent a heart procedure and is still recovering in Dallas.
The absence of even a gesture of bipartisanship was a reminder of the lasting political legacy of the civil rights battles. Since Democrats led the passage of civil rights legislation marchers pushed for in 1963, Republicans have struggled to recover black voters, leaving a stark racial divide in American politics.
"It's highly unlikely that any of us three over on my right would have served in the White House or be on this platform had it not been for Martin Luther King Jr. and his movement and his crusade for civil rights," Carter noted as he opened his remarks.
Reince Priebus, chairman of the Republican National Committee, said in a statement that "marchers came to Washington to claim their right to the American Dream, and we can't rest until that dream is in reach for every American."
Thousands marched along Constitution Avenue in the rain, past the Washington Monument and the World War II Memorial. Several wore sashes or carried signs indicating that they had also marched in 1963.
Linda Wills, 59, who attended the first march, said the recent Supreme Court ruling was a major blow to the cause.
"Here we are now 50 years later, and we've been set back," she said. "I'm going to remain a part of the movement until change comes, if the Lord lets me live long enough."
There were also young faces in the crowd, including the eighth-grade class from KIPP Ujima Village Academy in Baltimore.
"We came here to walk in the steps of our ancestors," said 13-year-old Shawn Carroll, who walked alongside 15-year-old Jordan Hopkins. "We came here today to show that we as people should have the same rights as other people."
Colleen Green said she participated Wednesday because she "missed the first one." She was less than 2 years old in 1963. But the Odenton woman was adamant about walking to the Lincoln Memorial on Wednesday.
"It's the right thing to do," she said. "I just felt that I needed to be here."