For decades after its founding, America was really two nations—one slave, one free. There were many reasons why the nation ultimately broke apart, but enslaved black people repeatedly risking their lives to flee their masters in the South in search of freedom in the North proved that the “united” states was a lie. By awakening northerners to the true nature of slavery, and enraging southerners who demanded the return of their human “property,” fugitive slaves forced the nation to confront the truth about itself. Their story, as told by Andrew Delbanco, the Alexander Hamilton Professor of American Studies, illuminates what brought us to civil war and the terrible legacies of slavery that remain.