Generals E. Kirby Smith and Braxton Bragg undertook this two-pronged movement, also known as the Kentucky Campaign, in the summer of 1862. Smith, commander of Confederate forces in East Tennessee, left Knoxville on August 14 and advanced into Kentucky with 10,000 men. He overcame the Union garrison under General William “Bull” Nelson in the Battle of Richmond on August 29 and 30. Two weeks later, Bragg moved north from Chattanooga with his 30,000-man Army of the Mississippi, roughly paralleling the movements of Smith to the east, forcing the surrender of the Union garrison at Munfordville, Tennessee.
The Union Army of the Ohio, 60,000 strong and under General Don Carlos Buell’s command, which had been pushing eastward toward Chattanooga, turned northward to pursue Bragg and Smith into Kentucky reaching Louisville on September 4. On October 1, The Union army advanced southeast in four columns to meet the armies of Bragg and Smith.
Believing the Union objective was Frankfort, Bragg detached a division to reinforce Smith. On October 7, Bragg directed his remaining soldiers moving north under General Leonidas Polk, to meet the approaching Federals near Perryville. The Battle of Perryville was a decisive Union victory, and Bragg ultimately retreated with his army to Knoxville.