At the Washington National Cathedral, area residents joined the many visitors who are in town for Saturday's March For Our Lives.
"If they're going to stand up, I'm going to stand with them".
Organizers of the voter registration drive hope to sign up at least 25,000 people at more than 800 marches, a potentially big boost for Democrats who generally favor more stringent gun control, including over sales of assault-type weapons, bump stocks that allow semiautomatics to fire like automatic weapons, and tighter access to guns by young people and people who are mentally ill.
The main rally organised by pupils in the wake of the Valentine's Day massacre at Marjory Stoneman Douglas High School will be held in Washington DC on Saturday.
Marches are also scheduled in the United Kingdom and Ireland, with a rallies in London, Newcastle, Edinburgh, Belfast and Dublin.
"I am so proud of these young people for standing up and doing something in a matter of months that people of my generation have spent decades trying to accomplish", Crane said.
On Friday, Trump signed a $1.3tn spending bill that includes modest improvements to background checks for gun sales and grants to help schools prevent gun violence.
"We can't ignore the issues of gun control that this tragedy raises". They've finally gotten to the point they realize they're the generation that can make a change.
"It's pretty simple for me", said Zoe Tate, 11, from Gaithersburg Middle School in Maryland, explaining why she marched in Washington.
Rallying outside the New Hampshire Statehouse in Concord, 17-year-old Leeza Richter said: "Our government will do more to stop us from walking out than it will to stop a gunman from walking in".
High School in Parkland, Florida are organising the massive protests in collaboration with the nonprofit organisation, "Everytown for Gun Safety".
"The fact that we have terror in schools all around the world, but especially in the USA, something needs to be changed", said Madison Browne at the Vancouver protest. "I understand the Second Amendment is important".
Polls indicate that public opinion nationwide may be shifting on an issue that has simmered for generations, and through dozens of mass shootings. We stand with all students, parents, co-workers, neighbors and loved ones who have been touched by gun violence in saying 'no more.' In many communities across the USA, gun violence is a daily occurrence. That's up from 61 percent who said the same in October 2016 and 55 percent when the AP first asked the question in October 2013.
Sam Robinson is the co-owner of Utah Gun Exchange.
Amnesty International U.K.'s director Kate Allen referred to the 1996 school killings at Dunblane Primary School in Scotland, in which 16 students and a teacher were killed.
Participation in USA elections by young voters is often low.