Alone among the societies that abolished slavery in the nineteenth century, the United States, for a moment, offered the freedmen a measure of politi… - Eric Foner

Lincoln asked the nation to confront unblinkingly the legacy of slavery. What were the requirements of justice in the face of this reality? What would be necessary to enable former slaves and their descendants to enjoy fully the pursuit of happiness? Lincoln did not live to provide an answer. A century and a half later, we have yet to do so.

Shortly before the 1860 election, Frederick Douglass offered a succinct summary of the dilemma confronting opponents of slavery like Lincoln, who worked within the political system rather than outside it. Abstractly, Douglass wrote, most northerners would agree that slavery was wrong. The challenge was to find a way of 'translating antislavery sentiment into antislavery action'. The constitution barred interference with slavery in the states where it already existed. For Lincoln, as for most Republicans, antislavery action meant not attacking slavery where it was but working to prevent slavery's westward expansion. Lincoln, however, did talk about a future without slavery. The aim of the Republican Party, he insisted, was to put the institution on the road to "ultimate extinction", a phrase he borrowed from Henry Clay. Ultimate extinction could take a long time. Lincoln once said that slavery might survive for another hundred years. But to the South, Lincoln seemed as dangerous as an abolitionist, because he was committed to the eventual end of slavery. This was why his election in 1860 led inexorably to secession and civil war.

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.