James M. McPherson's Tried by War is a perfect primer . . . for anyone who wishes to under stand the evolution of the president's role as commander in chief. Few histo rians write as well as McPherson, and none evoke the sound of battle with greater clarity. There is scarcely anyone writing today who mines original sources more diligently. In Tried by War, McPherson draws on almost 50 years of research to present a cogent and concise narrative of how Lincoln, working against enormous odds, saved the United States of America. --The New York Times Book Review