In the spring of 1864—150 years ago—the toil, sacrifice, and destruction of three years of Civil War merged into a swelling Union tide whose advance seemed inexorable, even if its success and destination remained in doubt. The Civil War became a whirlwind, rushing southward through Virginia and the Confederacy. Wilderness, Spotsylvania Court House, Cold Harbor, and Petersburg joined the lengthening list of the nation’s bloody battlefields. That divided nation and the world watched intently, for that spring and summer the final course of the war would be set.