Three years later, Cleburne bought his discharge and emigrated to the United States with two brothers and a sister. After spending a short time in Ohio, he settled in Helena, Arkansas, where he obtained employment as a pharmacist and was readily accepted into the town's social order. By 1860, he had become a naturalized citizen, begun the practice of law, and was very popular with the local residents. During this time, he became close friends with Thomas C. Hindman, another future Confederate general from Helena, and local Democratic politician.
Cleburne served at the Battle of Shiloh, the Battle of Richmond (Kentucky), where he was wounded in the face, and the Battle of Perryville. After the Army of Tennessee retreated to its namesake state in late 1862, Cleburne was promoted to division command and served at the Battle of Stones River, where his division advanced three miles as it routed the Union right wing and drove it back to the Nashville Pike and its final line of defense. He was promoted to major general on December 13.
During the campaigns of 1863 in Tennessee, Cleburne and his soldiers fought at the Battle of Chickamauga with a rare night assault and probably saved the Army of Tennessee from utter destruction by holding off a much larger Union force on the northern end of Missionary Ridge at the Battle of Chattanooga and at the Battle of Ringgold Gap in northern Georgia, in which Cleburne's men protected the Army of the Tennessee's rear as it retreated, escaping south and east to Tunnel Hill, Georgia. Cleburne and his troops received an official thanks from the Confederate Congress for their actions during this campaign.
Cleburne's strategic utilization of terrain, ability to hold ground where others failed, and his ability to use his smaller force to stymie the movements of the enemy earned him his fame during this time and gained him the nickname "Stonewall of the West." Federal troops were quoted as dreading to see the blue flag of Cleburne's Division across the battlefield from them.
It became obvious to Cleburne that the Confederate States were losing the war because of the drain on manpower and resources they were facing. In 1864, he dramatically called upon the leadership of the Army of Tennessee and put forth a proposal to emancipate slaves and enlist them in the Confederate Army to secure Southern independence. This proposal was met with extreme hostility by many, and was officially suppressed on order of Confederate President Jefferson Davis. Some have suggested that this was the reason that Cleburne would not receive further promotions, but the fact that he was not a West Point graduate and that he was Irish were also contributing factors.
His letter also predicted future events that continue to plague both the historical records of the war and the attitudes in the country:
Cleburne's remains were laid to rest at St. John's Church near Mount Pleasant, Tennessee, where they remained for six years. In 1870, he was disinterred and returned to his adopted hometown of Helena, Arkansas, with much fanfare and buried in Maple Hill Cemetery, overlooking the Mississippi River.
William J. Hardee, Cleburne's former corps commander, had this to say when he learned of his loss: "Where this division defended, no odds broke its line; where it attacked, no numbers resisted its onslaught, save only once; and there is the grave of Cleburne."
Several geographic features are named after Patrick Cleburne, including: