CNN  — 

The fourth annual Women’s March is Saturday, and streets across the country and around the world will be flooded with women and allies to advocate for women’s rights and equality.

Thousands of women first swarmed the streets of Washington on January 21, 2017, to march for women’s rights in the wake of Donald Trump’s inauguration as the 45th President of the United States. More than 1 million people participated nationwide in the 2017 march.

That march, the largest single-day protest in American history, has since become an annual event.

Here’s what you need to know about the Women’s March:

What is it?

The Women’s March began as a reaction to President Trump’s election and transformed into a movement to elect more women to public office and show their power at the polls. A wave of volunteers and activists joined different strands of the women’s movement, contributing to unprecedented wins for the Democratic Party by women of color in the midterms.

According to the Women’s March website, organizers adhere to eight “unity principles:” ending violence; protecting reproductive rights, LGBTQIA rights, worker’s rights, civil rights, disability rights and immigrant rights; and environmental justice.

The march “is committed to dismantling systems of oppression through nonviolent resistance and building inclusive structures guided by self-determination, dignity and respect.”

When is it?

The main march will take place in Washington on Saturday, January 18. Participants will gather on Freedom Plaza in downtown Washington at 10 a.m. and the march will begin 11 a.m. Hundreds of sister marches are taking place across the country and around the world.

Who’s participating?

The protest in Washington will be led by Las Tesis, the Chilean feminist collective known for their protest anthem, “Un Violador en Tu Camino,” which translates to “A Rapist in Your Path.” The group from Valparaíso, Chile, posted videos on its Instagram page of massive groups of women chanting the protest anthem on Chilean streets in late November and early December.

How’s the march being funded?

The Women’s March is funded by donations and partner organizations that pitch in resources, according to organizers.

What if you can’t attend the Washington march?

If you want to march but can’t make it to the main event in Washington, chances are there’s a sister march taking place in your city or close to you.

According to the Women’s March website, there are more than 300 events across the United States and in countries overseas, including Portugal, Nigeria, New Zealand and Germany.

If there’s not an event already planned for your city, the Women’s March have posted a guide on how to host your own march.