Some 150,000 people took to the streets in New York City on Saturday—joining millions of others in more than 800 cities around the world–demanding a change to America’s gun laws and promising to vote out any and all politicians who refused to take immediate action.

The protests were all part of the March For Our Lives movement, sparked by the angry cries of “enough is enough” from survivors of the Marjory Stoneman Douglas High School massacre in Parkland, Florida, last month.

In NYC the day began with a rally that extended more than a mile up Central Park West, with thousands more overflowing into the park itself. Speakers up on stage included survivors and relatives of those killed in Parkland, Las Vegas, and Sandy Hook, as well as representatives from Children of 911, Black Lives Matter, Life Up Guns Down, and Harlem Mothers.

The march itself lasted for hours, filling Central Park West, then 59th Street, and then Sixth Avenue down to Bryant Park, giving the finger to all Trump properties along the way, as is custom. And though the day was dominated by the words and actions of young people, there were plenty of politicians in the mix–including Mayor de Blasio, Governor Cuomo, and candidate Cynthia Nixon–as well as celebrities like Liev Schreiber and Paul McCartney.

When asked by CNN why he was out there, McCartney said: “One of my best friends was killed in gun violence right around here, so it’s important to me.”