The event was held on the 19th anniversary of the Columbine High School shooting, in which 13 people were killed.
Students from Washington-Lee High School in Arlington, Virginia, marched to the US Capitol in Washington, DC, joining other schools protesting outside the White House.
Over 2,600 school walkouts happened Friday, at least one event in every state, organizers said. Most were taking place at 10 a.m. local time and included a moment of silence for the victims of school shootings.
The movement's website explains the reason for the protest: "We are walking out for those who lost their lives to gun violence, to talk about the real problems our country is facing, and to find solutions the problems that our leaders have failed to address."