The Army of Tennessee's grueling and costly victory against a fortified Union encampment is expertly recounted in this engaging Civil War history.   In the fall of 1864, as William T. Sherman led Federal forces on his March to the Sea, Confederate General John Bell Hood chose to strike northward into Tennessee. There, he hoped to cripple the Federal supply infrastructure and strike the Army of the Cumberland under George Thomas. By defeating Thomas's army in detail, Hood hoped to force Sherman to come northward to the rescue.   On November 30, in a small country town called Franklin, Hood caught part of Thomas's army outside of its stronghold of Nashville. But what began as a promising opportunity soon turned grim. When subordinates voiced their concerns, Hood's response was unflinching. "If we are to die," said the Confederate officer, "let us die like men."   As wave after murderous wave crashed against the Federal fortifications, Hood's Army of Tennessee shattered itself. It eventually found victory--but at a cost so bloody and so chilling, the name "Franklin" would ever after be synonymous with disaster.   Historian William Lee White, whose devotion to the Army of Tennessee has taken him from the dense forests of northwest Georgia to the gates of Atlanta and back into Tennessee, now pens the penultimate chapter in the army's storied history in Let Us Die Like Men.