A pillar of radical activism in nineteenth-century America, Amy Kirby Post (1802–89) participated in a wide range of movements and labored tirelessly to orchestrate ties between issues, causes, and activists. A conductor on the Underground Railroad, co-organizer of the 1848 Rochester Woman’s Rights Convention, and a key figure in progressive Quaker, antislavery, feminist, and spiritualist communities, Post sustained movements locally, regionally, and nationally over many decades. But more than simply telling the story of her role as a local leader or a bridge between local and national arenas of activism, Nancy A. Hewitt argues that Post’s radical vision offers a critical perspective on current conceptualizations of social activism in the nineteenth century. While some individual radicals in this period have received contemporary attention—most notably William Lloyd Garrison, Frederick Douglass, and Lucretia Mott (all of whom were friends of Post)—the existence of an extensive network of radical activists bound together across eight decades by ties of family, friendship, and faith has been largely ignored. In this in-depth biography of Post, Hewitt demonstrates a vibrant radical tradition of social justice that sought to transform the nation.