From first to last the Army of the Potomac was unlucky. It fought for four years, and it took more killing, proportionately, than any army in American history, and its luck was always out; it did its level best and lost; when it won the victory was always clouded by a might-have-been, and when at last the triumph came at Appomattox there were so very, very many of its men who weren't there to see it.