The Battle of Chickamauga took place near Chickamauga Creek along the Tennessee-Georgia border on September 18-20, resulting in almost 18,500 Confederate casualties compared to just over 16,000 for the Union.  General George Thomas put up a valiant final effort for the Union, earning him the nickname, “the Rock of Chickamauga,” but he was eventually forced to withdraw with the already retreating Rosecrans to Chattanooga.  The Battle of Chickamauga was a tactical win for the Confederacy (its last in the western theater), but one that managed merely to buy time for the Confederacy and returned possession of Chattanooga to the Union.

Once back in the city again, an embarrassed and worried Rosecrans sent telegrams to his military and political superiors in Washington, D.C., informing them that “We have met with a serious disaster” (at Chickamauga), and “We have no certainty of holding our position here” (in Chattanooga).  President Abraham Lincoln characterized his general as “confused and stunned like a duck hit on the head.”  On the Confederate side, instead of attacking Chattanooga, Bragg ordered his troops to lay siege to the city, cutting off Union supplies so that they would be forced to surrender (like the Confederates at Vicksburg).  By mid-October, the Union troops were subsisting on half-rations (at best) and their horses were dying of starvation. 

Lincoln ordered reinforcements dispatched to the rattled Rosecrans from Mississippi, under the command of General William T. Sherman, and from Virginia, under General Joseph Hooker.  The president then created a new Division of the Mississippi, which included Tennessee, under the direction of General Ulysses S. Grant, the hero of the siege of Vicksburg.  Grant quickly replaced Rosecrans with Thomas as commander of the Army of the Cumberland, and the “Rock of Chickamauga” promised, “We will hold the town till we starve.”  Grant and his men arrived in the area on October 23, and within a week, aided by the arrival of Hooker, had opened up a supply route for the hungry Union troops in Chattanooga. 

Meanwhile, the Confederates had a serious leadership problem.  Subordinate officers were highly critical of Bragg’s decision to lay siege rather than to attack Chattanooga after their victory at Chickamauga.  General James Longstreet and other Confederate generals requested that President Jefferson Davis remove Bragg from his command, and General Nathan Bedford Forrest refused to serve under the “scoundrel.”  In early October, Davis felt compelled to visit Bragg’s headquarters in an attempt to ease the tensions.  At a meeting with Bragg, his four corps commanders asked Davis to replace him with another general.  Instead, the Confederate president removed Bragg’s harshest critics and agreed to Bragg’s proposal to send General James Longstreet with 15,000 men in an effort to retake Knoxville, Tennessee. 

Davis’s decisions left the leadership quarrel unsettled and seriously weakened the Confederate troop strength near Chattanooga.  By mid-November, Sherman had joined his Union comrades and the Confederate position seemed precarious.  Grant planned a coordinated attack, placing the main assaults on the enemy’s flanks, led by Sherman and Hooker on each end, with a frontal ruse by Thomas to attract Confederate attention and keep them from reinforcing their flanks.  The Battle of Chattanooga began on November 23 when Thomas’s troops captured Orchard Knob in the Confederate center.  The next day, Hooker’s men on the north took Point Lookout (later called the “Battle Above the Clouds”), but Sherman’s force had difficulty on the south flank, and Hooker’s advance soon stalled. 

On November 25, Grant changed the failing plan and ordered Thomas to charge the center.  The general sent 23,000 men in an assault reminiscent of the ill-fated Pickett’s charge of the Confederates at Gettysburg.  However, in this instance, the attacking force succeeded in breaking through the enemy’s trenches, and the Confederates retreated to higher ground.  The Union troops, though, were sitting ducks in their new position, so, without orders, they charged up the steep Missionary Ridge.  Aghast, Grant pointedly asked, “Thomas, who ordered those men up the ridge?”  Thomas sheepishly replied, “I don’t know.”  Amazingly, the charge was successful, and the adrenaline-pumped Union soldiers screamed “Chickamauga!  Chickamauga!” as the panicked Confederates ran for their lives.  Bragg was unable to reorganize his retreating army until it had traveled 25 miles southward toward Atlanta. 

At his own request, Bragg was relieved of duty, and Davis replaced him with General Joseph E. Johnston.  The losses on both sides at the Battle of Chattanooga were comparatively light:  under 6000 for the Union (out of 70,000) and under 7000 for the Confederacy (out of 50,000).  However, it was a tremendous tactical and strategic victory for the Union and defeat for the Confederacy.  The loss devastated Confederate morale, and gave the Union secure control of Chattanooga, from which General Sherman would later stage his campaign on Atlanta and his march to the sea.