A woman wearing pink pussy protest hat takes a part in the Women's March on Washington, following the inauguration of US President Donald Trump, in Washington, DC, US Jan 21, 2017. [Photo/Agencies]

Related: Over one million people stage massive anti-Trump protests across US

WASHINGTON — In a global exclamation of defiance and solidarity, more than 1 million people rallied at women's marches in the nation's capital and cities around the world Saturday to send President Donald Trump an emphatic message on his first full day in office that they won't let his agenda go unchallenged.

Many of the women came wearing pink, pointy-eared "pussyhats" to mock the new president. Plenty of men joined in, too, contributing to surprising numbers everywhere from New York, Philadelphia, Chicago and Los Angeles to Mexico City, Paris, Berlin, London, Prague and Sydney.

The Washington rally alone attracted over 500,000 people by the unofficial estimate of city officials — apparently more than Trump's inauguration drew on Friday.

The international outpouring served to underscore the degree to which Trump has unsettled people in both hemispheres.

"We march today for the moral core of this nation, against which our new president is waging a war," actress America Ferrera told the Washington crowd. "Our dignity, our character, our rights have all been under attack, and a platform of hate and division assumed power yesterday. But the president is not America. ... We are America, and we are here to stay."Turnout in the capital was so heavy that the designated march route alongside the National Mall was impassable. Protesters were told to make their way to the Ellipse near the White House by way of other streets, triggering a chaotic scene that snarled downtown Washington.

Around the world, women brandished signs with slogans such as "Women won't back down" and "Less fear more love." They decried Trump's stand on such issues as abortion, health care, diversity and climate change. And they branded him a sexist, a bully, a bigot and more.

"We want a leader, not a creepy tweeter," some marchers chanted in Washington. Others: "Welcome to your first day, we will not go away!"In Chicago, organizers canceled the march portion of their event for safety reasons after the overflow crowd reached an estimated 150,000. People made their way through the streets on their own anyway. In New York, well over 100,000 marched past Trump's home at glittering Trump Tower on Fifth Avenue. More than 100,000 also gathered on Boston Common, and a similar number demonstrated in Los Angeles.

In Miami, real estate agent Regina Vasquez, 51, brought a sign saying "Repeal and Replace Trump.""I believe that strength is in the numbers, and that we should all come out and not make Trump the new normal," she said.

All told, more than 600 "sister marches" were planned worldwide. Crowd estimates from police and organizers around the globe added up to more than a million.

"I feel very optimistic even though it's a miserable moment," said Madeline Schwartzman of New York City, who brought her twin 13-year-old daughters to the Washington rally. "I feel power."Retired teacher Linda Lastella, 69, who came to Washington from Metuchen, New Jersey, said she had never marched before but felt the need to speak out when "many nations are experiencing this same kind of pullback and hateful, hateful attitudes.""It just seemed like we needed to make a very firm stand of where we were," she said.

As the demonstrators rallied alongside the National Mall, Trump opened his first full day as president by attending a prayer service at the Washington National Cathedral, a tradition for the day after inauguration, and later visited the CIA. As he traveled around town, his motorcade passed large groups of protesters that would have been hard to miss.