City officials said they were expecting half a million people to join the protest in Washington, doubling their estimates as women arrived by bus and overcrowded subway trains to rally on Independence Avenue, at the heart of the US capital.
The turnout for the Women’s March on Washington was thought to have eventually matched – and even surpassed – the 800,000 that the District of Columbia officials estimated attended Mr Trump’s inauguration on Friday.
The gathering crowds created a sea of pink hats and brought the city to a standstill in an unprecedented display of opposition to a new president. In Washington and Chicago, the crowds grew so vast that marching became impossible.
America Ferrera, the actress, addressed the crowd gathered in Washington.
“We reject the demonisation of our Muslim brothers and sisters,” she said. “We condemn the systemic murder and incarceration of our black brothers and sisters. We will not ask our LGBT families to go backwards. We will not go from being a nation of immigrants to a nation of ignorance.
“We won’t build walls and we won’t see the worst in each other.”
Filmmaker Michael Moore and actress Scarlet Johannsson were among those who addressed the crowd in Washington.
The women’s march received support from Hillary Clinton, the candidate Mr Trump defeated. She thanked the protesters on Twitter “for standing, speaking and marching for our values.” Several Democratic members of Congress attended the Washington march. President Trump also got a glimpse of the protesters from the window of his limousine as he returned to the White House from a prayer service.
Some marchers wore “Nasty woman” T-shirts, quoting one of Mr Trump’s own comments about women.
They carried banners that covered the full range of concerns about the new president, from defending ObamaCare and abortion rights to protecting the environment.
Many had never marched before but said they were intent on showing the world — and perhaps reminding themselves — that “Trump was not America,” as one put it. The result was as much a celebration of diversity as a display of opposition.
Temple McDowell, a former Miss Utah who alleged Mr Trump kissed her without consent in the 1997 Miss USA pageant, explained that she wanted to stand up for victims of abuse everywhere.
“It’s not right for anyone, let alone the president, to speak about nor treat women in the way that he has.,” she said.
Organisers of the Saturday protests said women were gathering for nearly 700 sister marches, in every American state and on every continent, including Antarctica, where a group of 30 women and supportive men from an expedition ship staged a march in Paradise Bay – accompanied by gentoo penguins.
Linda Zunas, an analytics and market researcher from Oakland, California, who organised the Antarctica march said, ” I spent a month after the election mourning the impending damage to the earth that will be done. I felt I needed o do something to be part of the global movement.”
The actual marching had to be brief to limit any environmental damage but there was a note of humour injected into the serious message, with placards saying, “Penguins for peace’ and “Cormorants for climate”.
In New York, women, men and children of all ages massed on the streets chanting anti-Trump slogans. Jeanette Lee, a mother of three daughters, took an hour-long train ride to join the march in Manhattan.
“It’s important to be here because of my daughters. I want to teach them that if they want change, they need to be out there making that change.”