Pro-life demonstrators crowd National Mall in annual March for Life

(Fox News)

WASHINGTON – Anti-abortion demonstrators crowded the National Mall on Thursday for an annual march coinciding with a landmark U.S. Supreme Court decision that legalized abortion.

Demonstrators at the annual March for Life carried signs with slogans like "Defend Life," "I am a voice for the voiceless" and "Thank God my mom's pro-life." The march is held annually on the day that the Supreme Court announced its decision in the Roe v. Wade case in 1973 and ruled that the Constitution protects a woman's right to an abortion.

As demonstrators were packing the National Mall, Republicans muscled legislation through the House tightening federal restrictions on abortions. The White House warned that President Barack Obama would veto the measure, all but ensuring that it would not become law.

The vote came hours after lawmakers abruptly abandoned another bill banning most late-term abortions because a rebellion led by female Republican lawmakers left them short of votes.

Demonstrator John Castelot, 58, of Manchester, New Hampshire, said he was disappointed that Congress would not pass the bill banning most late-term abortions.

"After twenty weeks, that's halfway through a pregnancy," said Castelot, who said he has been coming to the march for about 10 years. "You'd think that would be a no brainer for people to support. I think the legislation was flawed."

After hearing from speakers who included several members of Congress, the crowd marched from the National Mall to the U.S. Supreme Court.

Rep. Cathy McMorris Rodgers, R-Washington, who has a 7-year-old son with Down syndrome, told the crowd her son has made her even more committed to the anti-abortion fight.

"Every child and every life is a gift," she said.

Other members of Congress at the event included: Rep. Chris Smith, R-New Jersey; Rep. Daniel Lipinski, D-Illinois, and Sen. Tim Scott, R-South Carolina.