We like to think that America is the good guy in any fight. That’s why this new documentary, A Night at the Garden, is so chilling. The 7-minute clip shows Americans goose-stepping, cursing the Jews, and in general, celebrating the rise of Nazism to a backdrop of a larger than life George Washington, flanked by swastikas.

Just how many antisemitic Americans gathered in New York’s Madison Square Garden, on that dark night in 1939? Read it and weep: 20,000 of them.