So you want to organize a very large protest march? There's no one better to ask than Leslie Cagan. Leslie has helped organize some of the biggest marches in recent history. To name just a few:

• the 1967 March on the Pentagon
• the 1982 anti-nuclear protest in Central Park—then the largest anti-nuclear protest and largest political demonstration in American history
• the 1987 March on Washington for Lesbian and Gay Rights
• the 2003 march against the Iraq War
• the 2004 protest around the Republican National Convention
• and the People’s Climate March in 2014.

I interviewed Leslie in November 2015. Both Leslie and I have lightly edited the text below for clarity.