On Dec. 15, 1864, Confederate Gen. John Bell Hood had the unfortunate job of going up against the Union's only undefeated general officer, Maj. Gen. George H. Thomas. Thomas, nicknamed "The Rock of Chickamauga" for preventing a disaster for the Union in 1863, would keep that record throughout the Civil War. After the two-day Battle of Nashville, his nickname would become "The Sledge of Nashville," after he effectively destroyed the Confederate Army of Tennessee. Sherman's Famous March to the...