Updated at 4:27 p.m.
Students hoisted "Stand United" signs. They chanted "''Hey, hey, ho, ho - the NRA has got to go" outside the White House. Others read the names of the Marjory Stoneman Douglas High victims aloud in a somber tribute.
At East Chapel Hill High School, senior Talia Pomp said one of her best friends attends Marjory Stoneman Douglas High and texted her during the rampage last month, leaving an everlasting impact on her.
"That personal connection made it like super real for me ... and this has to be the last one," said Pomp, who handed out orange T-shirts with #enough written on them to her classmates.
Some of her classmates aligned their desks in a circle to discuss gun violence in America. Above them hung an image of Che Guevara, a prominent communist figure in the Cuban Revolution who went on to become a guerrilla leader in South America and a universal symbol of revolution.
Most of the students at East Chapel Hill High walked out Wednesday morning.
"Bringing everyone together united under a common issue that we all face, and that we all could be potential victims of, was really important for our school," said senior Noah Clapacs. "Our school community may be at stake, and that's what we have to fight as."
These scenes played out across the country as students put down their pencils and pens and walked out of class to protest gun violence. Activists hoped it would be the biggest demonstration of student activism yet in response to last month's massacre in Florida.
Parkland High School outside Allentown, Pennsylvania, shares more than a name with the school in Parkland, Florida.
Stoneman Douglas freshman Daniel Duff, who survived the shooting by hiding in a closet but lost seven of his friends, is the cousin of Collin and Kyleigh Duff, who go to Parkland High in Pennsylvania. The Duff siblings have been selling #parklandforparkland bracelets, raising more than $10,000 for the Florida shooting victims.
Daniel Duff described what it was like to live through the shooting in a video that was shown at the rally.
"How many more mass shootings does it have to take for real change?" he said.
Parkland High students called for stricter gun laws, read short biographies of each of the 17 shooting victims and observed a moment of silence at 10 a.m. The gym was bathed in bright white light as students turned on their cellphone flashlights.
Collin Duff said it was important that Parkland High, a massive school of more than 3,200 students, show solidarity with the school in Parkland, Florida.
"It could have happened to anyone," he said. "It could have happened to us."