When Union and Confederate forces squared off along Bull Run on July 21, 1861, the Federals expected this first major military campaign would bring an early end to the Civil War. But when Confederate troops launched a strong counterattack, both sides realized the war would be longer and costlier than anticipated. First Bull Run, or First Manassas, set the stage for four years of bloody conflict that forever changed the political, social, and economic fabric of the nation. It also introduced the commanders, tactics, and weaponry that would define the American way of war through the turn of the twentieth century. This crucial campaign receives its most complete and comprehensive treatment in Edward G. Longacre’s The Early Morning of War. A magisterial work by a veteran historian, The Early Morning of War blends narrative and analysis to convey the full scope of the campaign of First Bull Run—its drama and suspense as well as its practical and tactical underpinnings and ramifications. Also woven throughout are biographical sketches detailing the backgrounds and personalities of the leading commanders and other actors in the unfolding conflict. Longacre has combed previously unpublished primary sources, including correspondence, diaries, and memoirs of more than four hundred participants and observers, from ranking commanders to common soldiers and civilians affected by the fighting. In weighing all the evidence, Longacre finds correctives to long-held theories about campaign strategy and battle tactics and questions sacrosanct beliefs—such as whether the Manassas Gap Railroad was essential to the Confederate victory. Longacre shears away the myths and persuasively examines the long-term repercussions of the Union’s defeat at Bull Run, while analyzing whether the Confederates really had a chance of ending the war in July 1861 by seizing Washington, D.C. Brilliant moves, avoidable blunders, accidents, historical forces, personal foibles: all are within Longacre’s compass in this deftly written work that is sure to become the standard history of the first, critical campaign of the Civil War.