From acclaimed Abraham Lincoln historian Harold Holzer, a groundbreaking account of Lincoln's grappling with the politics of immigration against the backdrop of the Civil War. In the three decades before the Civil War, some ten million foreign-born people settled in the United States, forever altering the nation's demographics, culture, and--perhaps most significantly--voting patterns. America's newest residents fueled the national economy, but they also wrought enormous changes in the political landscape, and exposed an ugly, at times violent, vein of nativist bigotry. Abraham Lincoln's rise ran parallel to this turmoil; even Lincoln himself did not always rise above it. Tensions over immigration would split and ultimately destroy Lincoln's Whig Party years before the Civil War. Yet the war would make clear just how important immigrants were, and how interwoven they had become in American society.