The mostly white crowd that gathered outside Salt Lake City's federal building hoisted signs reading "Black Lives Matter," and chanted for justice before wading into downtown traffic. In the historic Boston suburb of Lexington, Massachusetts, protesters with children in tow stood alongside others in their 80s.
Across the country, protesters angered at the killing of unarmed black men by white police officers have turned out in recent days, many in cities far removed from where the most highly publicized cases have played out. They are students and grandmothers, experienced protesters as well as novices, often as many white as black.
But while marchers speak emotionally about being galvanizing by this cause, both they and authorities on the fiery history of U.S. social protest are hard-pressed to figure where the demands for change will lead.
"Is this a movement or a moment?" said Marshall Ganz, a Harvard University lecturer whose perspective was shaped by participation in the 1964 Freedom Summer civil rights drive in Mississippi and then by 16 years working to organize migrant farm workers.
Following grand jury decisions not to indict police officers in the killing of Michael Brown in Missouri and Eric Garner in New York, he said the widespread protests are "kind of remarkable, all the different cities involved."
But "social movements ... are a combination of opportunity and intentionality," he said. They're about issues people were "already concerned about. But there are moments when they kind of shift."
Will marches keeping going and growing? That will turn on organizers' ability to funnel frustration over deaths into a push for concrete demands, said David S. Meyer, author of "The Politics of Protest: Social Movements in America," and a professor at the University of California, Irvine.
That is a path some individual protesters struggle to visualize. But their accounts of how they came to join protests show how an issue that for many was important, but abstract, has turned into something deeply personal.
Through the fall, Andrew McFadyen-Ketchum read about Brown's and Garner's deaths and was reminded of friends he knew growing up in a mixed-race neighborhood in Nashville, Tennessee. But his schedule teaching English at the University of Colorado and touring to promote a book of poems left little time to do more than ponder.
Then, a day or two before Thanksgiving, someone texted him about a march the NAACP planned 800 miles away in Missouri to protest the grand jury's decision not to indict officer Darren Wilson for Brown's death.
"I was just feeling like, man, I need to do something," said Ketchum, who is 33 and white. He had a little money in the bank from book royalties, so "I looked for flights to St. Louis and they were, like, less than $200 round-trip for the next day and I grabbed them." That night over dinner, when he hesitated, his wife encouraged him to go.
In Ferguson, he joined a crowd that would march from that city into rural towns, the protesters spending days walking along highways and sleeping on church floors. His was one of the few white faces, but other protesters embraced him. Used to hiking in thin Colorado air, he became the group's designated pacesetter.
Years before, McFadyen-Ketchum had volunteered to work on a U.S. Senate campaign and gone to Ukraine as an elections observer. But joining the march was decidedly different, a chance for honest conversation and camaraderie across races.
"It's been the greatest week of my life," he said, recalling how, when the marchers had their feet washed and their shoes anointed at a church, he had wept.
"Are you OK?" fellow marchers asked him.
"I'm just so overwhelmed with joy," he answered.
At 26, Rachel Tuszynski is hardly new to protest. She marched against the Iraq war in 2007 and, more recently, demonstrated in favor of legalizing medical marijuana. Then, last Thursday, Tuszynski and her girlfriend drove into downtown Chicago on an errand and, motivated by spontaneous curiosity, went looking for a march against police brutality that they'd heard about on the radio.
"We drove down Michigan Avenue until we couldn't," said Tuszynski. "I was in slippers ... and I heard helicopters and police and I just hopped out of the car," joining protesters shouting "Hands Up. Don't Shoot." When someone handed her a sign with the message, "Ferguson is Everywhere," she grabbed it.
"It's like I have an internal fire and I am deeply, deeply upset by injustice. To me, this is injustice," she said.
Tuszynski, who works as a cook in a restaurant and who shares Puerto Rican, Italian and Polish ancestry, acknowledges that it's not injustice that victimizes her directly.
And yet, with short-cropped hair that draws attention to her identity as a lesbian, she said she is often stared at by passersby and sometimes hassled. She has heard from black, male friends about being pulled over by police and ordered out of their cars for little if any apparent reason. While their experiences are different, it is easy to relate, she said.
So much so that in the days since Tuszynski has grown hoarse from shouting at protests and taken time off from work to participate.
"I want someone to hear us, that's all I want. I want people to know that Chicago stands with Ferguson, and stands with every black person in America who feels afraid."
Yvorn Aswad's family moved out of mostly black and Hispanic neighborhoods in South Central Los Angeles years ago for the suburbs. But gathering around the Thanksgiving table at a uncle's home in Azusa, somber conversation about the Brown and Garner killings served as a reminder of how their lives remains framed by race.
"My mother, who is the mother of three black sons, was devastated," by video of Garner, flailing against a police officer's chokehold, he said. It was "profoundly heartbreaking," he added.
Holiday plans had called for a movie after dinner. Instead, Aswad, a brother and his girlfriend, and a cousin went to bed early so they could wake up for a protest in Los Angeles.
Aswad, who is 25 and works as a health and wellness coordinator for a nonprofit organization, already knew the value of protest — having demonstrated over the years on local issues like the planned closing of a hospital.
And he has closely followed reports about the killing of unarmed black men.
But the Garner video triggered something much more visceral, something shared by his family and by the protesters he joined, first in front of the Los Angeles Police Department and then in suburban Riverside.
"We've grown up in an era where we elected Barack Obama and of being told we live in a post-racial America and yet we see black men and black women mistreated," he said. But protesting alongside other black men, as well as others who came in solidarity, countered that narrative.
"For me, it has been an entirely uplifting situation," he said. "We're going to do all that we can to make sure it doesn't fade."
Sarah Morton is white, 45 years old, and a playwright, maybe not the first person you'd expect to see in a protest to mark police confrontations with young, black men.
But she's also a native Clevelander, who was horrified last spring when city police officers chased two unarmed suspects into a schoolyard and fired more than 100 shots into their car, killing both. She worries about the students, most of them black, that she knows from her work as an artist-in-residence at Cleveland School of the Arts.
After a Cleveland police officer shot and killed a 12-year-old holding a pellet gun in a playground last month, just as the country was fixated by the killings in Missouri and New York, she felt the need to speak out.
"For me, protesting is a kind of antidote to despair," said Morton, who organized anti-war marches in the lead up to the U.S. invasion of Iraq. "I could've just sat here ... but you have to be with other people. You have to go out and collectively express yourself or otherwise it can be too much," she said.
Last Friday, Morton, who lives just outside the city in Cleveland Heights, joined a crowd in Public Square in the center of downtown, carrying a homemade sign: "Enough!"
The mix of races and ages in the crowd gave the march an energy that Morton hopes will be transformed into action.
"What People in Cleveland are trying to brainstorm about is how to really put pressure on our city officials to do more, to create real reform," she said. "But this is not going to go away, at least until things change."