Robert J. Cook is a professor of American history at the University of Sussex and author of Civil War Senator: William Pitt Fessenden and the Fight to Save the American Republic. William L. Barney is a professor of history at the University of North Carolina at Chapel Hill and author of The Civil War and Reconstruction: A Student Companion. Elizabeth R. Varon is a professor of history at the University of Virginia and author of Disunion! The Coming of the American Civil War, 1789-1859.