Hundreds of Canadian women, many wearing pink knit hats or carrying signs emblazoned with the maple leaf and the slogan "sisters of the north", filled the sidewalks of Washington, D.C. Saturday as they made their way to a massive rally for women's rights.

Residents came out onto their porches to shout words of encouragement and snap photos of the crowd. Others handed out free coffee.

"We're from Canada!" one woman shouted to a man who greeted the marchers from the front door of his home. "Really?" he replied incredulously. "See you there!"

Roughly 600 Canadians, most of them women, made the overnight trek on chartered buses from Toronto, Montreal, Ottawa and Windsor, Ont., to participate in what's being called the Women's March on Washington. Others made their way to the U.S. capital by car or plane.

The rally was billed as supporting women's rights rather than protesting Donald Trump, the newly crowned U.S. president, who was officially sworn in Friday.

City officials in Washington said the turnout estimate for the march on the National Mall stood at 500,000 people -- more than double the initial predictions. There were early signs across the city that the crowds could top those that gathered on Friday to watch Trump's inauguration.

Many Canadian participants said they were spurred to act by Trump's controversial comments during the election campaign.

Sadaf Jamal, 38, says many people have felt marginalized as a result of the campaign and she wants to help them "stand proud."

"I'm a Muslim woman and that is why I'm marching, because I want to empower all Muslim women," she said on a bus from Toronto.

"Why should we be marginalized? … There's nothing wrong with us. We are talented women, we are courageous women, we can be whatever we want to be."

A dual Canadian-American citizen, Elizabeth Wolfenden, said she cried for hours after Trump was elected.

The 18-year-old, who has many relatives in the U.S., said she initially planned to march with her mother but decided to make the trip alone after her mother suffered an injury.

The rally, she said, is her first trip alone.

"I just really want to take part in history," she said.

"I think this will be historical and I want to say that I was there, that I did something, that I tried to make a difference and I let my voice be heard, that I joined a movement that I think is really important."

Katina Binette drove from Montreal with four friends to show solidarity with the women's rights movement in the U.S.

Seeing the engagement, especially among youth, has been encouraging, she said.

Binette said her group was concerned they wouldn't make it after three of their friends were turned back at the border Friday night.

They were questioned for more than an hour and fingerprinted, she said. Border guards asked the three whether they were for or against Trump and their plans to take part in the march were taken as opposition, she said.

"It's pretty surprising, they all had valid Canadian passports and no criminal record," she said.

U.S. Customs and Border Protection would not confirm the incident citing the Privacy Act, but it said in an email to The Canadian Press that the agency "strives to treat all travellers with respect and in a professional manner, while maintaining the focus of our mission to protect all citizens and visitors in the United States."

Marches were also taking place Saturday in many major Canadian cities as well as smaller communities.

In Toronto, thousands gathered outside the Ontario legislature holding signs -- some attached to hockey sticks -- that called for respect for women's rights.

"I did the 50s. We are NOT going back there," read a sign carried by 87-year-old Cleo Corcoran, who said she has five daughters, 10 granddaughters and a great-granddaughter.

"Women are half the population and yet we are so often pushed to the back of the crowd," she said. "Now we've got to come in front."