By summer 1863, the Confederates knew that they were losing the Civil War. On July 4, 1863 alone, Robert E. Lee’s army retreated from Pennsylvania after losing the Battle of Gettysburg and the strategically important city of Vicksburg fell after a long siege. The loss of Vicksburg cut off almost a third of Confederate territory from the other two-thirds. In addition, W. S. Rosecrans’ Army of the Cumberland had just driven the opposing Confederate Army of the Tennessee (don’t confuse this with the Army of the Tennessee of the Union, which merged with the Army of the Cumberland after Chickamauga) out of it’s positions in the Tullahoma Campaign, and now threatened the strategically important rail junction of Chattanooga. If this city fell, then nothing could stop the Union from pushing into Georgia. The Confederates shifted troops from both Robert E. Lee’s Army of Northern Virginia and the Army of the Mississippi to save the city from Rosecrans’ approaching army.
Rosecrans was surprised when Braxton Bragg, the Confederate general who was repeatedly criticized by his subordinates for his incompetence, decided to give up Chattanooga without a fight. Rosecrans moved through Chattanooga and decided to pursue the Confederates, who appeared to be retreating. Instead, Bragg had decided to lie in wait and destroy the Federals as they emerged from the mountain passes after marching from Chattanooga. Rosecrans blindly pursued, and on the morning of September 18, 1863, the two armies where on opposite sides of the creek called Chickamauga, Native American for “River of Death.”
Bragg, because of his reinforcements from the other theatres of war, had a numerical advantage. This was the only major battle in which the Confederates possessed this, and so Bragg went on the offensive. On September 18, 1863, Bragg’s men captured some river crossings, but because of some bad coordination and Federal defense, this day of skirmishing did not result in any decisive fighting.
On September 19, 1863, the Federals began the first real day of fighting as George Thomas sent a division to move towards the creek. They drove back some of Nathan Bedford Forrest’s cavalry, which was then supported by infantry. The men began a confused fight all along the line. Many brigades lost touch with division or corps commanders in the thick forest. The first day of fighting ended with no major differences in the dispositions. However, over the night, many of Longstreet’s veterans from Virginia arrived by rail and took up positions. Bragg planned an attack for the next day. The Army of the Tennessee would attack successively from north to south, beating back the Federals. Rosecrans prepared defensive positions during the night, preparing for the attack he knew was coming.
On September 20, 1863, Bragg’s men attacked as planned, but with slight delays. The Federal line held back the Gray/Butternut tide well until late morning, when Rosecrans mistakenly believed he had a gap in his line when he didn’t. He shifted part of his line to cover this “gap,” but thus opening a new gap that really existed. Coincidentally, Longstreet launched an attack at this undefended sector in a major stroke of unprecedented luck. The Federals were driven back and flanked. Rosecrans, with corps commanders McCook and Crittenden thought that the army had been destroyed. They rode with haste to Chattanooga. However, in reality, George H. Thomas had managed to entrench in a horseshoe-shaped position on Snodgrass Hill. Repeated Confederate assaults in the afternoon failed to dislodge Thomas. In one of the Confederate attacks, Richard Kirkland, the “Angel of Marye’s Heights” (for his heroics at the Battle of Fredericksburg), and two of his companions ventured too far ahead up Snodgrass Hill. The other two men survived, but Kirkland died. Rosecrans ordered Thomas to make an orderly withdrawal that night (September 20, 1863), relinquishing the field to the Confederates.
The Aftermath: That night, Bragg refused to believe that he had won the battle! He felt he had suffered many casualties (about 15,000 for both sides.) As a result, he allowed the Federal Army to escape into Chattanooga safely. For his heroic defense that saved the Union army, George H. Thomas, the Virginian who fought for the Union, was nicknamed “The Rock of Chickamauga” and given command of Rosecran’s army. The Confederate army moved around Chattanooga to lay siege to the Federals, occupying Missionary Ridge and Lookout Mountain. These strategic sites would be the target of Grant’s attacks in the Battle of Chattanooga, November-December 1863. After that battle, Georgia was exposed to W. T. Sherman’s brutal “March to the Sea.”