Stephen Sears posits that General McClellans importance in shaping the course of the Union during the Civil War was matched only by that of President Lincoln and Generals Grant and Sherman. And yet the Young Napoleon has been relegated to the shadows by historians of that great conflict. The youngest in his class at West Point, McClellan was, by age thirty-five, commander of all the Northern armies; he fought the longest and largest campaign of the time and the single bloodiest battle in the nations history; at thirty-seven, he was nominated for the presidency of the United States by the Democratic party but was soundly defeated by Abraham Lincoln, whom McClellan held in contempt. Believing beyond any doubt that Confederate forces were greater than his and that enemies at his back conspired to defeat him, he equally believed that he was Gods chosen instrument to save the Union. Drawing entirely on primary sources, Stephen Sears has given us the first full picture of the contradictory McClellan, a man possessed by demons and delusions.