(CNN) -- Just steps away from the courthouse where a jury decided George Zimmerman's fate, demonstrators vowed that their fight wasn't over.
"Nationwide protest to demand justice," protesters chanted after the jury's not-guilty verdict in Sanford, Florida, cleared Zimmerman in the shooting death of Trayvon Martin.
It wasn't long before some appeared to be heeding their call.
Rallies started in cities like Los Angeles, San Francisco, Chicago and New York. Pockets of protests spilled into the early morning hours Sunday.
The verdict in the closely watched trial echoed far beyond Sanford's borders in a case that drew national attention and has been racially charged from the start.
"Only white life is protected in America," one protester in Washington shouted. Others chanted "No justice, no peace" as they marched, CNN affiliate WUSA reported. A crowd lined up outside the White House and sang "Amazing Grace."
In Dallas, protesters held signs that said, "Justice system is a joke."
In Chicago's Daley Plaza, protesters vowed to use technology to push for change.
"It's the 21st century. We've got Twitter. We've got Instagram. We've got Facebook, we've got all these things that our elders did not have," one woman told the crowd. "We have resources."
Most protests have been peaceful, though there were some reports of property damage.
"I think we should, frankly, right now be celebrating the fact that we've seen a generation of young people respond by using our system, raising their voices, but not using their fists," NAACP President Benjamin Jealous told CNN's "State of the Union" on Sunday.
The Rev. Jesse Jackson called for protests to continue, and to remain peaceful.
"There will be protests, but they must be carried out with dignity and discipline," he told CNN's "New Day." "Let no act discredit the legacy of Trayvon Martin. In the long run, we will prevail in the struggle for justice. Any act of violence could serve to undermine the innocent blood and moral authority of Trayvon. What will happen if there, in fact, are riots, it gives sympathy to Zimmerman, and discredits Trayvon. Trayvon deserves sympathy. Zimmerman and his school of thought does not."
Zimmerman's supporters applauded the jury for siding with the neighborhood watch volunteer's claims that he shot the teen in self-defense. Others said prosecutors failed to prove their case beyond a reasonable doubt.
Some viewed the trial as a referendum on race that confirmed what some said they knew all along.
"That's our society," Terri Weems said as she headed into church in Washington on Sunday morning. "We expected not to be given justice. We haven't been dealt justice all this time. ... It's very disheartening."
Donna Holmes-Lockett of Philadelphia said she was surprised by the verdict. Zimmerman should have been punished for the shooting, she said.
"As a mother of black males, I have three sons, it makes me nervous about the reaction of the public toward the situations. I felt like he should have got some kind of, something. He's just walking away free. He did shoot him. It's like it's OK," she said. "I think if it was a black crime on a black person, it would have been a different outcome."
CNN's Victor Blackwell, Emanuella Grinberg and Alicia Stewart contributed to this report.