After taking charge of the Union’s western armies in October of 1863, General Ulysses S. Grant focused on lifting the Confederate siege of Chattanooga, Tennessee, which had been in place since the Battle of Chickamauga in September. Grant opened the “Cracker Line” to bring supplies to the beleaguered Army of the Cumberland inside the city, and, in mid-November, brought William T. Sherman’s Army of the Tennessee into the city as well. On November 23, the reinforced Federals began to fight their way out, overrunning Orchard Knob and gaining a foothold for continued attacks against the Confederate line. The next day, Grant launched an attack on Lookout Mountain and captured it after six hours of fighting. On November 25, Grant ordered Sherman to attack Tunnel Hill. While Sherman’s initial attack was a failure, a second attack by General George H. Thomas managed to completely break the center of the Confederate line. This third victory in three days compelled a Confederate withdrawal and opened up the Deep South to a Union invasion.