During the 1860 presidential campaign, the thousands of young Northerners in the Wide Awake movement organized boisterous, torch-bearing brigades to push back against slavery. But others saw the group as a paramilitary force training to invade the South. Smithsonian historian Jon Grinspan examines how the nation crossed the threshold from a political campaign into a war—with many on both sides pointing to the Wide Awakes as the mechanism that got them there.