From the podium, Palestinian-American activist Linda Sarsour and a range of other community activists exhorted demonstrators to "keep resisting" and "keep motivated." Another New York rally is scheduled Wednesday night.
Arielle Datz, who works in publishing, said she took the day off -- dubbed "Day Without a Woman" -- to take part in the demonstration and described the speeches as "very inspiring."
"We hope it won't be four years... but we will keep it up as long as we have to," she told AFP in reference to Trump's four-year term.
Many men also were protesting, such as Corey Ford, who closed his small venture capital firm to take to the streets.
"Fifty per cent of our team, eight employees, and 50 per cent of the CEOs of our companies are women," he said. "This is a women's demo, anti-Trump is part of it but it's not all of it."
Guardian reported that around 10 protesters were arrested by the police in New York.
In Washington at Lafayette Park across from the White House, many of the several hundred demonstrators carried signs decrying Trump's order blocking US aid to foreign nonprofits that provide or actively promote abortions.
"Donald Trump has got to go!" and "This is what democracy looks like!" the crowd chanted.
Susanne Lowen, a 55-year-old baker, decried the president's plan to link foreign aid to a prohibition against disseminating information on birth control as "cruel and immoral."
Plenty of anger was also directed at other Trump administration policies.
Sheila Collins choked on her words when she tried to explain the many reasons she was protesting, ranging from Trump's refusal to release his tax returns to controversial statements by cabinet officials like Attorney General Jeff Sessions and Housing and Urban Development Secretary Ben Carson.
"Every day I wake up thinking, 'this can't be real,'" said the 40-year-old marketing director with a sign that read "Our Bodies, Our Lives, Our Vote."
"They are doing things to undermine our democracy," she said.
As the crowd streamed into Lafayette Park, knots of demonstrators broke off and paused to take selfies with the White House as a backdrop.
Police officers clad in black, several on bicycles, discreetly eyed the crowd from a distance.
For demonstrator Tess Thapalia, 20, the main issue was what she described as "reproductive justice."
"These are our bodies and we decide what to do with them. For anyone else to say what to do with them is truly shameful," said Thapalia, a college student from New York.
Hundreds of women also descended on the Utah State Capitol, urging lawmakers to come out and speak to them, the Guardian reported.
IWD march across the world
Women in other parts of the world also gathered on International Women's Day to demand equal pay.
In Brazil, hundreds of people slammed the government's new policies for being unfriendly to poor and rural women.
The demonstrators said the pension reforms and raising the retirement age of women would make it family farmers, who produce 70 per cent of the country's nutritional needs, would find it harder to stay on their land, Reuters reported.
Women across Poland also demanded equal rights in their everyday lives.
Similar demonstrations have been reported from Australia, the Philippines, Switzerland, Japan and Indonesia.
In Australia, women demanded abortion to be decriminalised in states such as New South Wales and Queensland.
In Spain, around 40,000 protesters took to the streets of Madrid on Wednesday to call for an end to domestic violence.
Gathered in the central square, the protesters carried posters reading "Justice" and "We are not all here" -- in reference to victims of violence who have lost their lives.
"Gender violence must end, equality must be attained and the 'glass ceiling' for women in business broken," Marta Garcia, a protester at the Madrid rally, told AFP.
In the last three months of 2016 there were 38,402 reports of domestic violence, marking a 14 per cent increase compared to the previous year, according to figures provided by a watchdog group.