In 1939, some 22,000 members of the German-American Bund—a pro-Nazi group—flocked to a rally in Manhattan’s Madison Square Garden, ostensibly to celebrate George Washington’s birthday. Isadore Greenbaum, a twenty-six-year-old resident of Brooklyn, snuck in to hear what was being said. At some point during a speech by the Bund’s leader, Fritz Kuhn, Greenbaum became so incensed by the anti-Semitic rhetoric that he rushed the stage, yelling “Down with Hitler!” As Philip Bump recounts, he was swarmed and beaten by a group of uniformed thugs until rescued by the police, who promptly arrested him. Video footage can be seen here:
When the U.S. entered World War II, Greenbaum joined the Navy, in which he served for the duration of the conflict. He recalled the Madison Square Garden incident in an interview with Stars and Stripes in which he claimed, apparently falsely, to have landed a punch on Kuhn.
Read more on Washington Post: https://www.washingtonpost.com/news/politics/wp/2017/10/17/when-american-nazis-rallied-in-manhattan-one-working-class-jewish-man-from-brooklyn-took-them-on/