The protest started on Pennsylvania Avenue, outside the White House.
Then the march began.
Once the protest made it to Washington Post's headquarters, the lobby reportedly went on lockdown.
Staffers took photos of the crowd from inside the building.
Jessica Testa is a national reporter for BuzzFeed News and is based in New York.
Contact Jessica Testa at firstname.lastname@example.org.
Got a confidential tip? Submit it here.