How does political change take hold? In the 1850s, politicians and abolitionists despaired, complaining that the "North, the poor timid, mercenary, driveling North" offered no forceful opposition to the power of the slaveholding South. And yet, as John L. Brooke proves, the North did change. Inspired by brave fugitives who escaped slavery and the cultural craze that was Uncle Tom's Cabin, the North rose up to battle slavery, ultimately waging...