The anti-police brutality and racism protests that have swept across the country since George Floyd’s death on Memorial Day constitute the largest movement in U.S. history, according to polling data and experts interviewed by The New York Times. Four recent polls suggested that 15 million to 26 million people have participated in demonstrations in 550 places. “I’ve never seen self-reports of protest participation that high for a specific issue over such a short period,” said Neal Caren, an associate professor studying social movements.

The Women’s March of 2017 had a turnout of 3 to 5 million in a single day and the civil rights marches of the 1960s had hundreds of thousands of participants. Protests to unseat government leaders typically succeed when they have 3.5 percent of the population, one crowd-counting expert told the Times.