The abolitionists of the mid-nineteenth century have long been painted in extremes--vilified as reckless zealots who provoked the catastrophic bloodletting of the Civil War, or praised as daring and courageous reformers who hastened the end of slavery. But Andrew Delbanco sees abolitionists in a different light, as the embodiment of a driving force in American history: the recurrent impulse of an adamant minority to rid the world of outrageous...