The United States Army won a great victory through a series of brilliant campaigns. The enemy’s capital and major cities were under U.S. control. The field armies were destroyed, the enemy’s government had fled and its leaders were captured or in hiding. All agreed that it was a great feat of American arms, and the Army paraded through Washington with its mission accomplished. Amidst the heady euphoria of victory, it was impossible for the President, Congress, the generals, the soldiers and the country at large to imagine that in a few years much of the fruit of the great victory would largely be squandered through a mismanaged postwar occupation. In the subsequent years, a vicious insurgency, shrewd political maneuvering, partisan domestic politics, insufficient resources and a lack of political, military and popular will resulted in the failure of U.S. postwar policy.In the years between 1865 and 1877, the U.S. Army and the American government mismanaged the occupation of the ex-Confederate states; the result was that most of the strategic political objectives of the “Reconstruction” were subverted or not obtained. The experience of the U.S. Army in the ex-Confederate states illustrates the challenges and complexity of postwar operations.For at least a decade after the end of the Cold War, a central theme of the senior leadership of the U.S. Army was that the Army’s core mission was “fighting and winning the nation’s wars.”1 This was often a euphemism for the point of view that the Army is not designed for unclear nation-building operations. However, the experience of Reconstruction makes clear the point that at the strategic level post-conflict operations are the continuation of the war at a lower scale of violence and with a greater role for strategic political policy. Post-conflict operations are a part of war; if the Army is to win the nation’s wars, it must have a robust postconflict capability. If the Army as an institution refuses to embrace this view of war and to plan and organize for it, it is doomed to repeat the failure of the occupation of the Confederacy.