If you look in pretty much any history of the Civil War that discusses the siege of Chattanooga that followed the Union defeat at the Battle of Chickamauga, you will find some assertion that General William S. Rosecrans, commander of the Army of the Cumberland, went into a state of depression which essentially destroyed his capacity for command. From an intelligent, aggressive commander he supposedly turned into a dazed wreck – his confidence shattered, his spirit broken, unable to take even the most basic steps to keep his army supplied and in fighting trim. The accepted history goes on to say that it required the energy of Ulysses S. Grant, who was appointed to overall command of Union forces in the region, to save Rosecrans' army. Grant relieved Rosecrans, replaced him with George H. Thomas, and promptly set about devising a remarkably clear plan for getting the supplies flowing. The energy and resourcefulness of Grant resulted in the opening of the “Cracker Line” in an incredibly short time, which saved the Army of the Cumberland. This is often, in fact, considered one of his more noteworthy accomplishments.