Andrew Delbanco, professor of American studies at Columbia University, has written a new book: The War Before the War: Fugitive Slaves and the Struggle for America’s Soul From the Revolution to the Civil War.

Like any good history, his tale of American social and political polarization over slavery, which led inexorably to civil war, offers fresh perspective on the present as well as the past. I interviewed him, via email, over several days in October.