Protestors turned up at hundreds of marches and rallies to express their outrage at the US Supreme Court's proposed scrapping of abortion.
The nationwide movement follows a leaked draft opinion suggesting the court's conservative majority would overturn the landmark Roe v. Wade ruling.
Activists spoke of a need to mobilise quickly because Republican-led states are poised to enact tighter restrictions.
In the nation’s capital, thousands gathered in drizzly weather at the Washington Monument to listen to fiery speeches before marching to the Supreme Court - which is now surrounded by two layers of security fences.
The mood was one of anger and defiance.
“I can’t believe that at my age, I’m still having to protest over this,” said Samantha Rivers, a 64-year-old federal government employee who is preparing for a state-by-state battle over abortion rights.
Caitlin Loehr, 34, of Washington, wore a black T-shirt with an image of the late Supreme Court Justice Ruth Bader Ginsburg’s “dissent” collar on it and a necklace that spelled out “vote.”
“I think that women should have the right to choose what to do with their bodies and their lives. And I don’t think banning abortion will stop abortion. It just makes it unsafe and can cost a woman her life,” Ms Loehr said.
From Pittsburgh to Pasadena in California, and Nashville in Tennessee to Lubbock in Texas, tens of thousands participated in “Bans off our Bodies” events.
Organisers expected that among the hundreds of events, the largest would take place in Chicago, New York and Los Angeles.
“If it’s a fight they want, it’s a fight they’ll get,” Rachel Carmona, executive director of the Women’s March, said before the march.
What is the opinion around America?
Polls show that most Americans want to preserve access to abortion - at least in the earlier stages of pregnancy - but the Supreme Court appeared to be poised to let individual states have the final say.
If that happens, roughly half of states, mostly in the South and Midwest, are expected to quickly ban abortion.
The battle was personal for some protesters.
Teisha Kimmons said she might not be alive today if she had not had a legal abortion when she was 15.
“I was already starting to self-harm and I would have rather died than have a baby,” she said.
At that rally, speaker after speaker told the crowd that if abortion is banned that the rights of immigrants, minorities and others will also be “gutted.”
Amy Eshleman, wife of Chicago Mayor Lori Lightfoot, said: “This has never been just about abortion. It’s about control.
“My marriage is on the menu and we cannot and will not let that happen.”
In New York, thousands of people gathered in Brooklyn’s courthouse plaza before a march across the Brooklyn Bridge to lower Manhattan where another rally was planned.
“We’re here for the women who can’t be here, and for the girls who are too young to know what is ahead for them,” Angela Hamlet, 60, of Manhattan, said to the backdrop of booming music.
The upcoming high court ruling in a case from Mississippi stands to energise voters, potentially shaping the upcoming midterm elections.
In Texas, which has a strict law banning many abortions, the challenger to one of the last anti-abortion Democrats in Congress marched in San Antonio.
Jessica Cisneros joined demonstrators just days before early voting begins in her primary runoff against US Representative Henry Cuellar.
The race could be one of the first tests over whether the court leak will galvanise voters.
Saturday's rallies came three days after the Senate failed to muster enough votes to codify Roe v. Wade.
Sponsors included the Women’s March, Move On, Planned Parenthood, UltraViolet, MoveOn, SEIU and other organisations.
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