When Abraham Lincoln expressed gratitude for the northern churches in the spring of 1864, it had nothing to do with his appreciation of doctrine, liturgy, or Christian fellowship. As a collective whole, the church earned the president's admiration because of its rabid patriotism and support for the war. Ministers publicly proclaimed the righteousness of the Union, condemned slavery, and asserted that God favored the Federal army. Yet all of this would have amounted to nothing more than empty bravado without the support of the men and women sitting in the pews. This creative book examines the Civil War from the perspective of the northern laity, those religious civilians whose personal faith influenced their views on politics and slavery, helped them cope with physical separation and death engendered by the war, and ultimately enabled them to discern the hand of God in the struggle to preserve the national Union. From Lincoln's election to his assassination, the book weaves together political, military, social, and intellectual history into a religious narrative of the Civil War on the northern home front. Packed with compelling human interest stories, this account draws on letters, diaries, and church records from 165 manuscript collections housed at 30 different archives and libraries, letters and editorials from 40 different newspapers, and scores of published primary sources. It conclusively demonstrates that many devout civilians regarded the Civil War as a contest imbued with religious meaning. But in the process of giving their loyal support to the government as individual citizens, religious Northerners politicized the church as a collective institution and used it to uphold the Union so the purified nation could promote Christianity around the world. Christian patriotism helped win the war, but the politicization of religion did not lead to the redemption of the state.