The Battle of Chickamauga was fought from September 19 to 20, 1863, and became one of the bloodiest battles of the American Civil War. Located in northwestern Georgia, the confrontation was a vital engagement in the Western Theater of the war. Confederate General Braxton Bragg launched an offensive against Union General William Rosecrans' Army of the Cumberland. The initial assault began with Confederate forces attempting to flank their adversaries and create openings in the Union lines. Heavy fighting erupted as the Union troops, though caught slightly off guard, attempted to hold their positions amidst the strong Confederate assault.

On the first day, the intensity of the battle escalated, with both sides suffering heavy casualties. The Union forces initially held their ground, but by the end of the day, the Confederate troops had gained significant territory, pushing the Union forces back towards Chattanooga. The tactical maneuvers and the engagement of reinforcements played a critical role in the ebb and flow of battle. Rosecrans' army comprised a mix of experienced soldiers and newer recruits, while Bragg's troops were more battle-hardened, affecting morale and effectiveness in combat.

As the sun set on the first day of fighting, the battlefield was littered with the grim evidence of war. The Union army's retreat was marked by confusion and disarray, laying the groundwork for the subsequent conflict on the second day. The first day's engagement highlighted the strategic importance of the Chickamauga region and reinforced the ongoing struggle for control over key locations in the South. Ultimately, it foreshadowed the even grimmer fighting that would occur the following day.