Especially in times of war Americans have claimed for their nation a unique world mission, often defining it in religious terms. James Moorhead analyzes a crucial episode of this patriotic piety through the behavior of four major Northern Protestant denominations in the 1860s. After examining the antebellum origins of the concept of America as a redeemer nation, he investigates the churches' use of familiar dogmas -- principally that of millennialism -- to interpret the experience of Civil War and Reconstruction.