In August 1862, two Confederate forces, commanded by Bragg and General Edmund Kirby Smith, entered Kentucky. The Rebels hoped to raise troops and recoup territory lost during the summer. The invasion started well when Bragg captured a Yankee garrison at Munfordville on August 28 and Smith routed a Union force at Richmond on August 30. Despite the victories, the Confederates were disappointed by the response they received from Kentuckians. Bragg’s army hauled 15,000 extra rifles to equip Kentuckians they hoped would join the Rebel army, but Union sentiment and presence were strong in the state. Buell’s army had 78,000 men, and another 80,000 Federal recruits were drilling in Louisville and Cincinnati, Ohio. With such a strong Union presence, many Kentucky residents were unwilling to take up with the Confederacy.
Buell marched 58,000 men toward Bragg’s army while sending another 20,000 to confront Smith. Buell caught up with the Confederates outside of Perryville on October 7. Bragg was installing a provisional government in Frankfort, so General Leonidas Polk deployed the Confederate army in front of the Union lines west of Perryville. Bragg arrived the next morning, perturbed because Polk had not yet attacked the Yankees. Bragg did not realize the size of the force he faced–he assumed it was a single corps and not the bulk of Buell’s army. He ordered a strike for the early afternoon, hoping to fold the Union’s left flank back upon the rest of the army. The plan nearly worked. The assault drove Federals under the command of Alexander McCook back in disarray, and an acoustic shadow prevented Buell, who was two miles away, from hearing the battle. When Buell was finally alerted, he rode forward and directed two brigades to effectively shore up McCook’s sagging line. A smaller Confederate attack against the right side of the Yankee line was turned back, and nightfall halted the fighting. Realizing that he was outnumbered, Bragg began a withdrawal.
The losses were heavy. Of 23,000 Yankees engaged in the battle, 4,200 were killed, wounded, or missing; of 15,000 Confederates involved, 3,400 were lost. Bragg retreated south to rejoin Smith, and the Confederates slipped back to Tennessee through the Cumberland Gap. Buell did not pursue, and as a result he was replaced by General William Rosecrans. The Confederates abandoned the invasion of Kentucky and it remained firmly in Federal hands for the rest of the war.