From their commander's tents, Robert E. Lee and Ulysses S. Grant plotted marches and countermarches through the mountains and forests of Virginia during the bloody summer of 1864. The two armies fought major battles at the Wilderness, at Spotsylvania Court House, and at Cold Harbor. In June, after a failed attack on Petersburg, which lay south of Richmond, the two armies dug entrenchments and prepared for a siege. Two weeks later a Confederate cavalry force under Jubal Early mounted a raid through Maryland and into the District of Columbia, in sight of the Capitol dome, but it was turned back while President Abraham Lincoln watched the fighting from the parapets of Fort Stevens. Early's daring raid and the skillful maneuvering of the Army of Northern Virginia could not disguise a crucial fact: The Confederacy was slowly but certainly retreating, down the Virginia roads...