Tens of thousands of people have paraded across a bridge in Selma, Alabama to commemorate the 1965 "Bloody Sunday" march.
The US has been marking the 50th anniversary of a turning point in the civil rights movement there.
In contrast to the police violence that marked the original march half a century ago, the mood today was often celebratory and at times festive.
An estimated 70,000 demonstrators cheered, sang "We Shall Overcome" and carried signs as they walked across the Edmund Pettus Bridge.
Bloody Sunday on 7 March 1965 took its name from the beating that roughly 600 peaceful civil rights activists sustained at the hands of white state troopers and police who attacked them with batons and sprayed them with tear gas.
Among the crowds today were demonstrators who took part in the 1965 march, as well as others calling for immigration and gay rights.
US President Barack Obama visited Selma yesterday and declared the work of the US civil rights movement advanced but unfinished in the face of ongoing racial tension.
"Fifty years from Bloody Sunday, our march is not yet finished, but we're getting closer," said Mr Obama, the first black president of the US, as he stood near the bridge.
The anniversary comes at a time of renewed focus on racial disparities in the United States.
There has been anger over law enforcers' treatment of black civilians, among them 18-year-old Michael Brown, whose killing by a white police officer in Ferguson, Missouri, last year sparked widespread protests.
On Friday, Tony T Robinson Jr, a 19-year-old black man who appeared to be unarmed, was shot dead by a white police officer in Madison, Wisconsin, sparking protests there.
US Representative John Lewis, who led the march across the bridge 50 years ago and was knocked out by a state trooper, told NBC's "Meet the Press" today that what happened that day had led to lasting changes in civil rights.
"When I go back, I remember the bridge for me is almost a sacred place," the Georgia Democrat said.
"That's where some of us gave a little blood and where some people almost died.
"What happened on that bridge has changed America forever."
