A Stillness at Appomattox, which won the Pulitzer Prize in History, is the crown of the trilogy: the final campaigns of 1864–65 rendered with an accumulated weight that comes from having earned the reader's investment across three volumes. Catton understood that the Army of the Potomac was not just a military organization but a community, one that developed its own culture, its own grievances, its own stubborn pride, and that understanding is what lifts these books above ordinary military history into something closer to literature.