The largest set of demonstrations ever held in the U.S. is widely considered to be the Women’s March on January 21, 2017 — the day after Donald Trump’s presidential inauguration.
Women’s March (2017)
Estimated turnout: Between 3.3 million and 5.2 million people across the U.S.
Largest single-day protest in U.S. history
Main issues: Women's rights, reproductive rights, immigration, healthcare, LGBTQ+ rights, racial justice, and opposition to Trump’s policies
Number of events: Over 650 marches took place in all 50 states