March for Our Lives organizers estimate 800,000 protesters attended the gun-control demonstration in Washington, D.C. on Saturday.
If they're correct, the event would be the largest single-day protest in the history of the nation's capital. The total is bigger than the inaugural Women's March, which brought 500,000 to D.C., according to the Washington Post.
The number doesn't include large rallies in cities such as Boston, Houston, Minneapolis and Parkland, Fla., the site of the Valentine's Day attack at Marjory Stoneman Douglas High School that left 17 people dead.
Organizers of the March for Our Lives rally had hoped to exceed the half million protesters mark. The Women's March, which took place the day after Trump's inauguration, is considered the biggest one-day protest in recorded history, according to the Washington Post.
Other large protests in D.C. history include the 500,000 to 600,000 people who demonstrated against the Vietnam War in D.C. in 1969. The March on Washington for Jobs and Freedom on Aug. 28, 1963, drew about 250,000 people to D.C. where Martin Luther King Jr. delivered his famous "I have a dream" speech. And the Million Man March in 1995 garnered estimates of between 450,000 to 1.1 million people, according to the Encyclopedia Brittanica.