Narratives that paint minorities as dangerous to society are often used to justify the need for collective discrimination and violence. These narratives emerge after pivotal events and shape discriminatory behavior for many generations. This paper investigates the effects of the Civil War on race relations in the US South from 1865 to today and the narratives used to maintain it. We show that in places that lost more White men during the Civil war, more Black men were lynched, and more people voted for racially discriminatory lawmakers. We claim that this happened because this shock increased the perceived likelihood that Black men and white women could interact. This lent credibility to the narrative that Black men are "sexual predators" and a threat to White women. We show that in places with a larger shock, the "sexual predator" narrative was more often spoken by politicians, was more prevalent in newspapers, and was more often used to justify violence.