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 are scheduled to speak. Actress Kathleen Turner is 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."