Arthur Schlesinger, Jr. challenged the underlying premise of prevailing Civil War scholarship. The South, he pointed out, had shown no evidence of a willingness to end slavery; indeed, over time it had become ever more hysterical in its defense. With one eye firmly on the recent past, Schlesinger insisted that a society closed in support of evil could not be appeased, and if it was worth a war to destroy Nazism, surely it was worth one to eradicate slavery. But not until the 1960s, under the impact of the civil rights revolution, did historians en masse repudiate a half-century of Civil War scholarship, concluding that the war resulted from an irreconcilable conflict between two fundamentally different societies, one resting on slavery, the other on free labor. Historians pushed Emancipation to the center of their account of the Civil War, and it has remained there ever since.