Planning started fewer than three months ago from the home of a grandmother in Hawaii in the wake of the unexpected election results. Now, on President Trump’s first full day in office, the Women’s March on Washington is here — and it’s expected to be massive and the biggest demonstration tied to the Trump inauguration.

Upward of 500,000 women are expected to gather near the Capitol on the intersection of Independence Avenue and Third Street SW this morning. (Here’s a bit more about the origins of the march.)

The march is broadly about a demand for equal rights for women after the Democratic Party’s Hillary Clinton, the first woman nominated for president by a major party, was defeated in the November election. But in recent weeks, the march’s organizers have defined it with a progressively liberal agenda and signed on groups like Planned Parenthood as co-sponsors. The platform calls for ending violence against women, workers’ rights, reproductive rights, environmental justice, immigrant rights and more.

The inclusion of reproductive rights in the platform has angered antiabortion activists, who feel that they too are feminists and this march now excludes. Many antiabortion activists still plan to attend the march to participate and make their stances on abortion clear. (Read more about the debate of whether there is a place for antiabortion women in the Women’s March here.)

The planning of the march highlighted many rifts within the feminist movement. Still, march organizers say this is intended to be a positive, forward looking march. And there will be scores of celebrities to mark the occasion. Janelle Monáe will perform, Scarlett Johansson and Ashley Judd will make appearances. And activists Angela Davis and Michael Moore and D.C. Mayor Muriel E. Bowser (D) will also be speaking. (Find the full list of speakers here.)

And before you head over make sure to read our rundown of all the logistics you need to know.

The rally will run until about 1:15, and after that, the participants will begin marching west to The Ellipse park, just south of the White House.