Thousands of abortion-rights opponents are expected to descend on the National Mall on Friday to participate in the 2013 March for Life.
Organizers expect more than last year's crowd of 400,000 people to attend the event.
The March for Life is arguably the most high profile anti-abortion protest. It is in recognition of the Supreme Court's Roe v. Wade decision in 1973.
In 2012, House Speaker John Boehner (R-Ohio) and House Majority Leader Eric Cantor (R-Va.) addressed the crowd at the event. House leaders are expected to play a smaller role at the 2013 March for Life. Earlier in January, former Sen. Rick Santorum (R-Pa.) announced he would speak at the rally. Santorum, who ran for president last year, has been an outspoken opponent of abortion rights.
"I am looking forward to joining hundreds of thousands of Americans who believe that every life has value and every life must be protected," Santorum said in announcing his participation at the march. "We are a pro-life country, and the March for Life is an important opportunity for us to send a message to our elected officials that they must support policies that foster a culture of life."
The event begins on the National Mall at 12 p.m. The route goes along Constitution Avenue to the Supreme Court building on Capitol Hill.