Rep. Cori Bush, D-Mo., shared a personal story at the Washington, D.C., march, recounting when, as a young adult, she was in a relationship with an abusive partner who owned guns.

"He did not approve of the way I was cooking … we began arguing, he started to hit me. I decided to run out of the apartment," Bush said. "As I ran, I remember thinking to myself, why isn’t he chasing me? … When I turned back for a moment … I heard shots. Shots fired. But I didn’t know if they were aimed at me. Until they started whizzing past my head."

"That moment of horror, it stays with me," Bush said.

"It's so deeply traumatic and completely preventable," Bush said, referencing the boyfriend loophole, red flag laws and universal background checks.

Bush said, "We will never give up our push to save lives."

Manuel Oliver, whose son, 17-year-old, Joaquin was killed in Parkland, said in Washington, D.C., "Our elected officials betrayed us and have avoided the responsibility to end gun violence."

He said, "If lawmakers who have the power to keep us safe from gun violence are going to avoid taking action," then he's calling for a nationwide strike of schools, from elementary to college.

"Avoid attending school if your leaders fail … to keep us safe," he said. "Avoid going back to school if President Biden fails to open a White House Office of Gun Violence Prevention so that we can finally give this issue the attention that it deserves."

Oliver appeared on stage with David Hogg, a Parkland survivor and March For Our Lives co-founder, who vowed, "This time is different."

"This is not a political issue -- this is a moral issue," Hogg said.

He suggested combatting gun violence the way the U.S. addressed cigarettes.

"With cigarettes, we didn’t just change the laws -- we addressed why people want to smoke in the first place," Hogg said. "We have to address how people get guns and why they feel the need to pick them up in the first place. We must address the fact that the reason why communities like Parkland don't have shootings on a daily basis isn't because we necessarily have the strongest laws … we have some of the most resources."

New York Attorney General Letitia James joined a march in Brooklyn, tweeting, "We will fight every single day until we get the common-sense gun reforms this nation needs to end gun violence and save lives."

Washington, D.C., Mayor Muriel Bowser told D.C. protesters she's frustrated because "we have been here before."

"We're not asking for a lot. We're asking to drop off our children at school without having to worry that someone will bring an AR-15 into their classroom. We are asking to go to the grocery store without worrying that someone will be shot dead by a gunman who is filled with hate. We are asking to let our children go to the playground without worrying that a car will drive by, firing a high-capacity magazine," the mayor said. "We're done asking. We're demanding change and we're demanding change now."

She urged Americans "who share our values to let their senators know that they neither need to make change now-- or get out of our way."