Allan Nevins . Ordeal of the Union , 2 vols. (New York: Charles Scribner’s Sons, 1947). The Emergence of Lincoln , 2 vols. (New York: Charles Scribner’s Sons, 1950). The War for the Union , 4 vols. (New York: Charles Scribner’s Sons, 1959–71). These eight volumes are a magisterial account of the crisis-laden years from the Mexican War to Appomattox, covering social, economic, political, and military events in compelling prose.

David M. Potter . The Impending Crisis, 1848–1861 (New York: Harper & Row, 1976). The best single-volume survey of the political events that led to secession and war.

Shelby Foote . The Civil War: A Narrative , 3 vols. (New York: Random House, 1958–74). A superbly readable military history by a novelist who did a massive amount of historical research.

Bruce Catton . The Centennial History of the Civil War , 3 vols. (Garden City, N.Y.: Doubleday and Co., 1961–65). Fast-paced chronicle of the fighting on the battlefield and the infighting in the political capitals of Washington and Richmond. Mr. Lincoln’s Army (Garden City, N.Y.: Doubleday and Co., 1951). Glory Road (Garden City, N.Y.: Doubleday and Co., 1952). A Stillness at Appomattox (Garden City, N.Y.: Doubleday and Co., 1953). Catton’s superb trilogy on the Army of the Potomac emphasizes the gritty determination of private soldiers despite the incompetent commanders who led them so often to defeat until Grant finally took charge.

Douglas Southall Freeman . R. E. Lee: A Biography , 4 vols. (New York: Charles Scribner’s Sons, 1934–35). A classic study in leadership and command. Lee’s Lieutenants , 3 vols. (New York: Charles Scribner’s Sons, 1942–44). The story of the Army of Northern Virginia seen through the eyes of its principal officers.

Bell Irvin Wiley . The Life of Johnny Reb (Indianapolis: Bobbs-Merrill Co., 1943). The Life of Billy Yank (Indianapolis: Bobbs-Merrill Co., 1952). Thoroughly researched and superbly written studies of the common soldiers in both armies.