WASHINGTON — The day after what many had assumed would be the inauguration of the first female president, hundreds of thousands of women flooded the streets of Washington, and many more marched in cities across the country, in defiant, jubilant rallies against the man who defeated her.
Protesters jammed the streets near the Capitol for the main demonstration, packed so tightly at times that they could barely move; in Chicago, the size of a rally so quickly outgrew early estimates that the march that was to follow was canceled for safety.
In Manhattan, Fifth Avenue became a tide of signs and symbolic pink hats, while in downtown Los Angeles, shouts of “love trumps hate” echoed along a one-mile route leading to City Hall, with many demonstrators spilling over into adjacent streets in a huge, festival-like atmosphere.
The marches were the kickoff for what their leaders hope will be a sustained campaign of protest in a polarized nation, riven by an election that raised unsettling questions about American values, out-of-touch elites and barriers to women’s ambitions.
On successive days, two parallel and separate Americas were on display in virtually the same location. First there was President Trump’s inauguration, his message of an ailing society he would restore to greatness aimed at the triumphant supporters who thronged Washington on Friday.
Then on Saturday, in what amounted to a counter-inauguration, the speakers, performers and marchers proclaimed allegiance to a profoundly different vision of the nation. They voiced determination to protect a wide array of rights that they believe Mr. Trump threatens, and that they thought only recently were secure.
“Thank you for understanding that sometimes we must put our bodies where our beliefs are,” Gloria Steinem, the feminist icon and an honorary chairwoman of the march, told the throngs gathered in Washington. “Pressing ‘send’ is not enough.”
To mobilize a progressive movement reeling from Hillary Clinton’s defeat, organizers deliberately broadened the platform beyond longstanding women’s issues such as abortion, equal pay and sexual assault to include immigrant rights, police brutality, mass incarceration, voter suppression and environmental protection.
But the march’s origins were in the outrage and despair of many women after an election that placed gender in the spotlight as never before.
Mrs. Clinton assertively claimed the mantle of history, offering herself as the champion of women and families, and calling out her opponent for boasting of forcing himself on women in a recording that prompted a national conversation about sexual assault. In a sly allusion to the crude remarks Mr. Trump made on the tape, many marchers, women and men alike, wore pink “pussy hats” sporting cat ears.
The mood, though, was festive and buoyant. In Washington, demonstrators old and young pushed strollers and hoisted children onto their shoulders or guided elderly parents through the milling crowds. They waved handmade signs: “Hate Does Not Make America Great,” “I Will Not Go Back Quietly to the 1950s,” and “I’m 17 — Fear Me!” They chanted, “This is what democracy looks like.’”
Emma Wendt, 13, came with a large group of family and schoolmates from Kensington, Md., for a simple reason: “being part of history.”
The marchers were confronting a president who has appointed just a handful of women to his cabinet and inner circle, and who has pledged to nominate a Supreme Court justice who opposes abortion rights and dismantle a health care act that covers contraception. His appointees have track records of voting to cut funding for domestic violence, opposing increases in the minimum wage and restructuring Medicaid — moves that disproportionately affect women and minorities.
Precise crowd counts were difficult to come by, but in total, attendance at the marches across the United States and the world easily surpassed one million. In New York, they set off from a plaza near the United Nations and ended within a couple of blocks of Trump Tower, holding signs reading “Resist the Groper-in-Chief,” “Babes Against Bigots” and “Yuuuge Disaster.”
In Boston, the Boston Common, a gently rolling park ridged by brownstones in the shadow of the state Capitol, morphed into a sea of pink hats on Saturday morning. Music boomed around the park, the whole scene nodding to this city’s history of protest. “Revolution begins in Boston,” one sign said.
Looking out at an admiring crowd, which contained some signs reading “Warren 2020,” Senator Elizabeth Warren conjured up the image of Mr. Trump’s being sworn in the day before.
“The sight is now burned into my eyes forever,” Ms. Warren said, adding, “We will use that vision to fight harder.”
Yet women did not protest — or vote — as a bloc. About 53 percent of white women voted for Mr. Trump, according to exit polls, and many said his demeaning comments about women mattered less to them than their belief that he had the independence, temperament and business experience to bring about change, restore well-paying jobs and protect America’s borders.
The marches came a day after confrontations between anti-Trump protesters and the police led to more than 200 arrests in Washington. But Saturday’s demonstrations were peaceful, and counterprotests were few. In St. Paul, one man was arrested after marchers reported he had “sprayed irritants” into the crowd, the police said.
By midafternoon, the target of the protests had not said anything about the marchers, verbally or on Twitter. Though the Washington march ended within sight of the White House, and some demonstrators passed by his recently-opened hotel, Mr. Trump did not cross paths with the crowd.
After attending the inauguration on Friday, Mrs. Clinton was not seen at the march, which had strong echoes of her campaign appearances, including some of the same celebrities, performers and slogans. She did, however, acknowledge the moment on Twitter.
“Thanks for standing, speaking & marching for our values @womensmarch,” she wrote. “Important as ever. I truly believe we’re always Stronger Together.”
The marches captured the potential and the perils for the progressive movement — whether it can frame its message to appeal to new generations and whether it can translate protests into action locally and nationally.
Plans for Saturday’s march in Washington began as Facebook posts just after the election by a retired lawyer in Hawaii and a fashion designer in New York, both of whom are white and had no experience organizing protests. Soon, protests flooded the feeds urging them to diversify. In the end, a triumvirate of African-American, Latina and Muslim women assumed leadership.
The march’s initial struggles echoed broader debates in the movement about whether the courting of new demographic groups alienated the white working-class voters who had carried Mr. Trump to victory, or whether white women had betrayed gender solidarity by voting for him.
Yet on Saturday, these tensions did not deter a multiracial, multigenerational turnout at the marches.
Mothers marched with daughters and granddaughters; whole families, including husbands and sons, marched arm in arm.
One extended family that gathered in Washington was inspired by its 100-year-old matriarch, Sylvia Fein, who at the last minute decided that it would be too physically daunting for her to march.
“I’ve been voting for president since F.D.R. and I don’t remember ever feeling this way about a person,” said Ms. Fein, a retired accountant and painter in Philadelphia.
Her grandniece, Mikhael Tara Garver, 37, who traveled to the march from Brooklyn, recalled how her family had reacted after the election: “We were all calling my great-aunts, because we all knew how important Hillary was to them and how important surviving to see that moment was for them.”
Another family came from Baltimore, sisters, daughters and in-laws alike. “We have to get away from fear,” said Lureen Grace Wiggins, 49. Her daughter, Eden, 17, was exhilarated by the size of the crowd: “When you’re out here and people see you, they know you care.”
The march was rich in historical allusions — most deliberately, the 1963 march led by Dr. Martin Luther King Jr. But it echoed many other marches as well, including those in the 1970s that brought hundreds of thousands of women to the streets championing an Equal Rights Amendment that was ultimately defeated, and those from the late 1990s on for abortion rights, culminating in a 2004 March for Women’s Lives that organizers said drew more than one million to the capital.
Saturday’s march happened to come just six days before quite a different one: the annual March for Life by opponents of abortion.
But perhaps the most apt analogy, said Ellen Fitzgerald, the author of “The Highest Glass Ceiling,” was to the 1913 suffragists’ march on Washington, timed to coincide with the inauguration of President Woodrow Wilson. Led by the renowned suffragist Alice Paul, it featured a lawyer, Inez Milholland, riding a white horse down Pennsylvania Avenue, 24 floats, nine marching bands and even luminaries like Helen Keller. The women were hooted, jeered and roughed up by the police, generating congressional hearings and public sympathy. They won the vote seven years later.
Faye Wattleton, the former president of Planned Parenthood, said that women had always had to regroup, even after they thought battles were won. “This is not new,” she said. “We have to go back to the battlefield and re-fight the wars against women.”