By noon, it was impossible to move easily through the crowd. Teens waved homemade signs (“Hunting Season is Over”; “No, I’m Pretty Sure Guns Kill People”) and huddled together for photos. Poppy Fleming, a nine-year-old student at Hartwood Elementary, in Stafford County, Virginia, stood with Deborah and Michael Fleming, her grandparents. She held up a sign decorated with the names and locations of various mass shootings. In the middle, she’d written, in magic marker, “Am I Next?”

“We can teach her about civil disobedience,” Deborah said. “We can teach her how to vote.”

“Yes!” Poppy shouted. “Nine years away.” She was wearing a black knit hat with “Resist” stitched along the brim. She told me she’d gotten it at Busboys and Poets, a community space founded by Anas Shallal, an Iraqi-American artist and activist.

Further Reading New Yorker writers on the March for Our Lives.

After every mass shooting, there’s a public outcry, but it frequently fades without real progress; something feels profoundly different this time. The energy on the street was crackling, undeniable. How do you define or explain a tipping point? The night before, on CNN, I watched the parents of Lauren Milgram, a Sandy Hook survivor—Lauren was seven years old when she encountered an active shooter at her elementary school, and hid in a bathroom with her classmates and teacher—tell a reporter they had been “too polite” after the incident. Young people have certainly been instrumental to political upheavals before—in 1960, in Greensboro, North Carolina, four black men, none older than nineteen, sat down at a segregated Woolworth’s lunch counter and refused to leave (a portion of that lunch counter is now on display here, less than a mile from the rally, in the National Museum of American History). At this particular moment, they feel like our only hope for change.