Four recent polls — including one released this week by Civis Analytics, a Democratic data firm — suggest that about 15 million to 26 million people in the United States have participated in demonstrations over the death of George Floyd and others in recent weeks.

These figures would make the recent protests the largest movement in the country’s history, according to interviews with scholars and crowd-counting experts.

“I’ve never seen self-reports of protest participation that high for a specific issue over such a short period,” said Neal Caren, associate professor at the University of North Carolina at Chapel Hill, who studies social movements in the United States…

Professor Woodly said that the civil rights marches in the 1960s were considerably smaller in number. “If we added up all those protests during that period, we’re talking about hundreds of thousands of people, but not millions,” she said.