<human>:  Why did the anti-war movement start?
<bot>: The anti-war movement started in the 1960s as a protest against the Vietnam War. The anti-war movement was started by people who felt that the United States was making a mistake by sending troops to Vietnam. Many of these protesters were college students, who were not old enough to fight in the war, but they still felt that the war was wrong. They protested by wearing buttons that said “I am not a number” and they held demonstrations in the streets.