A crowd the Boston mayor's office estimated to be about 150,000 strong – almost double what organizers forecast – gathered on Boston Common Saturday morning to listen to local political leaders before processing through the Back Bay.

Robust as “Boston Women’s March for America” was, it constituted just a fraction of the worldwide expression of solidarity for progressive political causes. Those issues, for the most part, represent the antithesis of Donald Trump’s nationalist agenda: equal pay for equal work, reproductive choice, police and criminal justice reform.

Boston Common was full of shades of pink, signs, and self-proclaimed "nasty women."
Meredith Nierman/WGBH News

The nation’s largest gathering was in Washington, DC where an estimated 500,000 rallied. Dublin, London, Berlin and hundreds of other cities saw crowds dominated by women, but containing sizable numbers of men. All told, estimates of world-wide participation hit 3 million.

One thing seemed to be almost universal, though: The pink knitted caps known as "pussyhats" among the marchers, in protest of Trump's past comments about women.

Among the elected officials on the Boston stage were U.S. Senators Elizabeth Warren and Edward Markey, Boston Mayor Marty Walsh, and Attorney General Maura Healey.

The prevailing mood was positive, upbeat, celebratory – and occasionally funky and sassy.

"I'm making a statement. It's just clothes, really, and hair. It doesn't make a difference. Women are wearing men's clothes now. More power to them." -Dave Margeski, Woburn, MA
Paris Alston/WGBH News

Throughout the crowd, there was no mistaking the resolve to oppose much of the Trump agenda and resist the efforts of the Republican controlled Congress to move the nation in a more conservative direction.

“Organized people will overcome organized money every time,” said Carol Rose, the ACLU Massachusetts executive director.

Sen. Warren, with full-throated feistiness vowed, “We will not build a stupid wall.”

Even more animated than Warren was Mayor Walsh who – in the course of calling on the crowd to all become activists – said, “It’s not what we do today that matters, it’s what we do tomorrow.”

"Donald Trump has a dream," warned Sen. Markey, "that one day our nation will have no more Muslims, or mosques, or Social Security or Planned Parenthood."

At day's end the organizers of the march issued the following statement, claiming an even higher total of participants: "Today, we were so proud to stand in solidarity with 175,000 people in Boston. United by more than 600 sister marches happening throughout the world, we sent a clear message to elected leaders that we are a country that stands for equality, dignity and justice. We thank the City of Boston, all public safety officials, and our thousands of marchers for a peaceful, positive event."

In terms of events such as the Women's March For America, it's rhetorical to say that a crowd is massive and people are spread out as far as the eye can see, but in Washington DC this was literal.

The event grew from humble origins — a simple Facebook invitation after Election Day — to the much more massive demonstration seen Saturday. By the time marchers hit the streets, the Women's March on Washington developed a broad platform of progressive political positions, a slate of celebrity performers and a series of sister marches planned across the world — on all seven continents.