"We are the pro-life generation! We are the pro-life generation!" The chant could be heard along Constitution Avenue, as cold weather in the nation's capital did not deter the masses from taking part in the 2015 March for Life.

The massive crowds – consisting largely of young people – swarmed downtown Washington, D.C., praying, marching and witnessing to life.

Crowds were estimated at upwards of 200,000 for the annual march, which is held on or around Jan. 22 each year to mark the anniversary of the 1973 Roe v. Wade Supreme Court decision that mandated legal abortion nationwide.

Pro-lifers flooded Twitter as well, posting pictures of themselves with life-affirming messages and the hashtag #WhyWeMarch.

"I march for love. I march to speak for the unborn babies who cannot speak for themselves," tweeted one participant, Tiana DeLorge.

"Because human rights apply to all humans," said another attendee, Carla Burlando.

Priests, seminarians and religious showed up in large numbers. A few bishops even attended as well, traveling from across the country to be present at the event.

"Every life is a gift!" tweeted Bishop James D. Conley of Lincoln, who posted pictures of himself with march participants.

As in previous years, the crowds were notable for their high number of students. Christendom College in Virginia, Franciscan University of Steubenville, Ohio, and Ave Maria University in Naples, Florida were among the dozens of schools with significant representation at the event.

Also present were individuals who have suffered firsthand the effects of abortion.

"I march for the women I lied to when I worked in the abortion clinic," read one participant's sign.

Other marchers held banners saying, "I regret my abortion" and "Men regret lost fatherhood."

At a rally preceding the march, speakers offered messages of unity and hope, proclaiming that every life is a gift.

"We have come to stand for the pre-born who could not stand for themselves. We have come to celebrate life and to mourn the millions of babies killed in abortion," said March for Life president Jeanne Monahan.

"We have come to tell the world that abortion is wrong. It is the taking of innocent life. It has to stop."