Updated

Thousands of people, many holding signs with names of gun violence victims and messages such as "Ban Assault Weapons Now," gathered in front of the Capitol on Saturday for a March on Washington for Gun Control.

Marchers were led by Mayor Vincent Gray and other officials Saturday morning, and the crowd stretched for about two blocks along Constitution Avenue. Police blocked off half the road.

Participants held signs reading "Gun Control Now" and "Stop NRA," among other messages. Other signs were simple and white, with the names of victims of gun violence.

About 100 residents of Newtown were expected at the march. It was organized in response to the December shooting there that killed 20 first-graders and six teachers.

Kara Baekey of Norwalk, Conn., said she immediately thought of her two young children when she heard about the shooting. She said she decided she must take action, and that's why she joined Saturday's march.

"I wanted to make sure this never happens at my kids' school or any other school," Baekey said. "It just can't happen again."

James Agenbroad, 78, of Garrett Park, Md., carried a handwritten sign on cardboard that read "Repeal the 2nd Amendment." He called it the only way to stop mass killings because he thinks the Supreme Court will strike down any other restrictions on guns.

"You can repeal it," he said. "We repealed prohibition."

Molly Smith, the artistic director of Washington's Arena Stage, and her partner organized the march. Organizers said that in addition to the 100 from Newtown, they expected buses of participants from New Jersey, New York and Philadelphia. Others are flying in from Seattle, San Francisco and even Alaska. A rally was planned on the monument grounds at noon.

While she's never organized a political march before, Smith said she was compelled to press for a change in the law. The march organizers support President Barack Obama's call for a ban on military-style assault weapons and high-capacity ammunition magazines as well as for universal background checks for gun sales. They also want lawmakers to require gun safety training for all buyers of firearms.

"With the drum roll, the consistency of the mass murders and the shock of it, it is always something that is moving and devastating to me. And then, it's as if I move on," Smith said. "And in this moment, I can't move on. I can't move on.

"I think it's because it was children, babies," she said. "I was horrified by it."

After the Connecticut shootings, Smith posted something on Facebook and drew more support to do something. The group One Million Moms for Gun Control, the Washington National Cathedral and two other churches eventually signed on to co-sponsor the march. Organizers have raised more than $46,000 online to pay for equipment and fees to stage the rally.

Lawmakers from the District of Columbia and Maryland were scheduled to speak Saturday. Actress Kathleen Turner was expected to appear, along with Marian Wright Edelman of the Children's Defense Fund and Colin Goddard, a survivor from the Virginia Tech massacre.

Smith said she supports a comprehensive look at mental health and violence in video games and films. But she said the mass killings at Virginia Tech and Aurora, Colo., and Newtown, Conn., all start with guns.

"The issue is guns. The Second Amendment gives us the right to own guns, but it's not the right to own any gun," she said. "These are assault weapons, made for killing people."