On the eve of the Civil War and after, Illinois was one of the most significant states in the Union. Its history is, in many respects, the history of the Union writ large: its political leaders figured centrally in the war’s origins, progress, and legacies; and its diverse residents made sacrifices and contributions—both on the battlefield and on the home front—that proved essential to Union victory. The documents in Illinois’s War reveal how the state and its people came to assume such a prominent role in this nation’s greatest conflict. In these crucial decades Illinois experienced its astonishing rise from rural frontier to economic and political powerhouse. But also in these years Illinois was, like the nation itself, a “house divided” over the expansion of slavery, the place of blacks in society, and the policies of the federal government both during and after the Civil War. Illinois’s War illuminates these conflicts in sharp relief, as well as the ways in which Illinoisans united in both saving the Union and transforming their state. Through the firsthand accounts of men and women who experienced these tumultuous decades, Illinois’s War presents the dramatic story of the Prairie State’s pivotal role in the sectional crisis, as well as the many ways in which the Civil War era altered the destiny of Illinois and its citizens. Illinois’s War is the first book-length history of the state during the Civil War years since Victor Hicken’s Illinois in the Civil War, first published in 1966. Mark Hubbard has compiled a rich collection of letters, editorials, speeches, organizational records, diaries, and memoirs from farmers and workers, men and women, free blacks and runaway slaves, native-born and foreign-born, common soldiers and decorated generals, state and nationally recognized political leaders. The book presents fresh details of Illinois’s history during the Civil War era, and reflects the latest interpretations and evidence on the state’s social and political development.