In the decades after the Civil War, Americans—shaken by economic and social disruption—sought safety in aggressive, tribal partisanship, resulting in the closest, most violent elections in U.S. history. By the century's end, reformers had restrained this wild system, yet voting rates crashed and never fully recovered. Here Jon Grinspan charts the era's unruly politics through the lives of a remarkable father-daughter dynasty: the radical congressman William "Pig Iron" Kelley and his fiery, Progressive daughter Florence Kelley. In telling the tale of what it cost to cool our republic, Jon Grinspan reveals our divisive political system's capacity to reinvent itself.