Their procession began Saturday morning outside a Planned Parenthood office on Commonwealth Avenue.
Stephen Fournier, 75, a demonstrator from southern New Hampshire, said he came to stand for what he views as a legal and moral truth.
“From the moment of conception, it’s a life — it’s a baby,” Fournier said, holding a sign that read “Personhood today.” “Life is protected by our Constitution, but you have to admit that it’s life at the moment of conception. That’s where people differ.”
Soon after marchers began gathering outside Planned Parenthood, they were confronted by counter protesters.
A woman passed through the crowd and chanted: “My body, my choice! Abortion is health care!”

Nearby, men dressed in formal wear prayed to themselves and held rosary beads.
Another group of men and women who oppose abortion recited a prayer in Spanish.
Fournier said he wasn’t bothered by counter protesters mocking the marchers.
“If that’s what they want to do, go right ahead,” he said. “When you stand up for what you believe in, people are going to disagree. Let’s have an open discussion.”
Last year, nine people were arrested and charged with disorderly conduct after they clashed with the demonstrators.
The 2024 event occurred shortly after President Trump’s reelection and reflected the high stakes many placed in women’s reproductive rights since the US Supreme Court overturned Roe v. Wade three years ago.
During his first term, Trump installed three Supreme Court justices who voted to overturn the landmark court ruling that affirmed a woman’s right to an abortion.
By 10:40 a.m. on Saturday, a band had arrived with some members wearing berets and large drums slung across their shoulders or worn like a front-facing backpack. Others carried bagpipes, in full Scottish regalia.
A handful of volunteers in bright pink vests stood guard in front of the clinic as the ranks of the anti-abortion demonstrators swelled.
A man dressed in a horse costume, carrying a microphone and speaker, approached demonstrators as he sang “Girls Just Want to Have Fun.”
He called himself the “Planned Parenthood pony” and tried to drown out march organizers using a bullhorn to direct demonstrators.
“These guys could be at an orphanage, but instead they’re here bullying women,” he said.
He also talked about Trump’s ties to Jeffrey Epstein, the sex offender who killed himself in prison in 2019 as he awaited trial on federal sex trafficking charges.
“Trump was on the Jeffrey Epstein plane,” the pony sang to the tune of the Village People song, “Y.M.C.A.” as a priest knelt in prayer nearby.
As the march made its along the Boston University campus, Christine Doherty, 49, said she was there “to stand and march in solidarity with pro-life men.”
“We’re at Boston University right today, and a lot of these colleges are indoctrination camps, and they teach the wrong things to young adults,” said Doherty, who holds a degree from BU’s School of Education.
“I really hope that the college students who see us out here today get to know that there is another choice — the correct choice, which is to choose life and not baby murder,” she said.
As marchers set off on their procession to the Boston Common, police officers dressed in yellow vests rode bicycles along the edges of the column. Other police officers on motorcycles drove ahead of the people marching to stop motor vehicle traffic.
As the march reached the spot where Commonwealth Avenue intersects with St. Paul Street, demonstrators prayed the Hail Mary in unison.
Counter protesters, some wearing clown noses, lined the sidewalks. One group blasted “The Imperial March” from “Star Wars” and “Pop Goes the Weasel.”
Doherty mocked the counter protesters.
“They’re dressed appropriately as clowns, because that’s what they are — clowns,” she said.
Police officers were positioned along the perimeter of the procession, keeping the marchers and counter protesters separated.
Chris Lennon, 63, of Plymouth, walked ahead of the march carrying a sign that read, “Her Body Her Choice.”
“It really bothers me that people use their religion to justify their politics,” said Lennon.
Opposing abortion, he said, is about “controlling women,” he said.
Jaime Moore-Carrillo can be reached at jaime.moore-carrillo@globe.com. Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her @lauracrimaldi. Nathan Metcalf can be reached at nathan.metcalf@globe.com. Follow him on Instagram @natpat_123.