Many writers saw the US Civil War as an apocalypse, but they construed that apocalypticism in different ways. I approach the apocalyptic archive of Civil War literature by tracking the aesthetic techniques authors employed to represent the war’s cataclysmic dimensions and the political, religious, and historical meanings they assigned to the nation’s convulsion. My readings show how reflecting on the Civil War as an apocalypse occasioned formal innovations that pushed nineteenth-century writing in unexpected directions and how apocalyptic representations of the conflict went hand in hand with millenarian appraisals of the nation’s, and sometimes the hemisphere’s, future. Ultimately, I argue that such apocalyptic and millennial thought is inextricable from the history of race relations in America, for any appraisal of wartime upheaval is also necessarily an overt or tacit reflection on the history and legacy of slavery. I make this argument by considering writing by William Wells Brown, Matthias Carvalho, John De Forest, Emily Dickinson, Frederick Douglass, Frances E. W. Harper, Ruban His Sacred Nest, Abraham Lincoln, Herman Melville, Henry Timrod, and Walt Whitman.