Up to 200,000 women from across the United States will converge on Washington, DC, the day after the inauguration of US President-elect Donald Trump, to protest his policies and attitude towards women.
They are just part of a wave of demonstrations across the country, peaking tomorrow and on Saturday, as many Americans - upset at Mr Trump's policy agenda and incensed that he won the November 2016 election despite trailing his rival Hillary Clinton by almost three million in the popular vote - take to the streets.
Reflecting the bitterly polarised political environment, around 60 Democratic Party lawmakers have said they will boycott the inauguration tomorrow - a movement triggered by Mr Trump's Twitter retaliation on civil rights icon John Lewis for saying he did not consider Mr Trump a legitimate president.
The protests are being organised by dozens of groups, including the Act Now To Stop War And End Racism (Answer) Coalition, the Occupy Movement and a group called #DisruptJ20 which says it wants to "shut down" the inauguration.
The groups represent a broad array of interests, including pro- choice and civil rights groups worried about the President-elect's ultra-conservative agenda and team.
But Mr Trump's supporters will not be inactive either, and there are some jitters over security, especially in Washington, where the groups will encounter one another. Those in support of Mr Trump include a bikers' group that is roaring in from around the country and will assemble at John Marshall Park near the Capitol on inauguration day.
Number of people - pro- and anti-Trump - expected to visit Washington tomorrow and Saturday.
Number of police officers, paramilitary National Guard and military troops to be deployed.
The city authorities expect around one million people, both pro- and anti-Trump, to visit Washington tomorrow and on Saturday.
Well over 15,000 police officers, paramilitary National Guard and military troops will be out in a huge security net, with buildings in the area sanitised and "locked down" from today. Heavy trucks filled with sand or water will be placed at access points to deter vehicles speeding into the zone - a swathe several blocks wide, from the Capitol to the Washington Monument and the White House.
Sporadic protests have already begun on a few street corners. In a bulletin this week, risk consultancy firm Control Risks warned that "significant disruption should be anticipated" tomorrow.
Protests against Mr Trump will also be held at the Trump International Hotel in New York, led by Mayor Bill de Blasio and drawing celebrities such as Michael Moore and Mark Ruffalo. New York, Mr Trump's home town, is a liberal bastion that voted overwhelmingly against him. Mr de Blasio has asked people to "remind our next president of his home town's values".
In Park City, Utah, actress Chelsea Handler will lead a women's march on Saturday at the Sundance Film Festival. "Women are under a right-wing political assault, and I intend to fight back with all my might against a Republican president, a Republican Congress and the radical, religious right," she wrote in an article this week.
Ms Lisa Klimek Mills, 54, who lectures on wildlife biology at the University of Montana at Missoula, is trading the quiet, snow-clad ridges and fir trees outside her window for the grey streets of Washington this weekend.
Ms Mills, as well as her 15-year-old daughter Linnea and niece, will use her frequent flier miles to fly six hours and rent a car to get to the capital, so they can join the women's march on Saturday.
"I was really disappointed by the election," Ms Mills said. "A lot of things are changing, and I did not think we could lose ground as a nation, on women's rights, and tolerance of diversity and immigrants. Comments he (Mr Trump) has made about women have embarrassed our nation. This march gives us a place to put our worries, make a statement, make a difference."
Within political circles in Washington, the mood ranges from jubilant triumphalism in the Trump camp, to foreboding in the Democratic Party camp and the rank and file of the outgoing administration.
At a lecture on "Trumpism" on Tuesday at the conservative Heritage Foundation in the capital, Republican Newt Gingrich drew a laugh from the audience when he said that this week would be "a period that we will all understand later by having lived through it".
The ebullient 73-year-old former Speaker of the House added: "What they (Democrats) are going to feel on Friday is, 'this is the world we thought we would have, and this is the world we are getting'."
He then dramatically spread his arms as wide as he could. "And it is that big a gap."