No Kings” organizers described the events as a “nationwide day of defiance” against President Donald Trump and authoritarianism.

The parade was the spectacle event Trump had long wanted. It also helped sparked the largest mass opposition to him since his inauguration 145 days earlier.

The parade, honoring the Army’s long-planned 250th anniversary celebration and coinciding with Trump’s 79th birthday, is set to step off from the Lincoln Memorial under the threat of stormy weather in Washington and protests around the country tied to a turbulent week of immigration enforcement that has involved military deployment in Los Angeles.

Millions were expected to gather in “No Kings” demonstrations in over 1,500 cities on Saturday, the same day the Army is celebrating its 250th anniversary on Trump’s birthday.