As the Confederacy crumbled under the Union army's relentless "hammering," Federal armies marched on the Rebels' remaining bastions in Alabama, the Carolinas, and Virginia. General William T. Sherman's battle-hardened army conducted a punitive campaign against the seat of the Rebellion, South Carolina, while General-in-Chief Ulysses S. Grant sought to break the months-long siege at Petersburg, defended by Robert E. Lee's starving Army of Northern Virginia.

In Richmond, Confederate President Jefferson Davis struggled to hold together his unraveling nation while simultaneously sanctioning diplomatic overtures to bid for peace. Meanwhile, President Abraham Lincoln took steps to end slavery in the United States forever.

Their Last Full Measure relates these thrilling events, which followed one on the heels of another, from the battles ending the Petersburg siege and forcing Lee's surrender at Appomattox to the destruction of South Carolina's capital, the assassination of Lincoln, and the intensive manhunt for his killer. The fast-paced narrative braids the disparate events into a compelling account that includes powerful armies; leaders civil and military, flawed and splendid; and ordinary people, black and white, struggling to survive in the war's wreckage.