Marchers took to the streets in 800 cities around the world as part of March For Our Lives Saturday.
The focus now shifts to Capitol Hill as politicians continue to debate gun control.
Mark Kelly, husband of Arizona Congresswoman Gabby Giffords, said he believes that the students who organized the event could bring about change, but it won't be easy. Giffords was shot in 2011 when a gunman opened fire at a campaign event.
"I would warn them not to get discouraged," Kelly said. "You know, this is often two steps forward and one step back. They have a plan and this is not the last you're going to see of these kids."
Martha Raddatz sat down with students in Tuscon. Two of those students were classmates of Christina Taylor-Green, who was 9 when she was shot and killed at Giffords' campaign event.
"I knew immediately that we needed to do something to show Christina and her family that we cared," said Canyon Del Oro High School student Rebecca Sands.
Many said they hope Saturday's march marks the beginning of a political movement.
"If you look at the voter turnout for our age, it's embarrassing," said Cameron Kasky on Fox News Sunday. "So, the fact that this movement has so many people realizing that it's important to get out to the polls is what I think is one of the best things we've accomplished."
"This is led by the youth and it is lead for the youth," Delaney Tarr said on Fox News Sunday. "And if we can encourage these people to take action, to be participating in our society and our politics, then that's going to encourage our voters to actually turn out."
Gun control debate rages on after March For Our Lives