General Hardee took the 7th Arkansas Battalion with him when he transferred his command to Kentucky and organized the Confederate Army of Central Kentucky and Colonel Cleburne was placed in command of a new brigade which included his 15th Arkansas, the 6th Mississippi, and the 23rd, 24th and 35th Tennessee Regiments. After the losses of Fort Henry and Fort Donelson in February 1862, Confederate General Albert Sidney Johnston withdrew his forces into western Tennessee, northern Mississippi, and Alabama to reorganize. and then retreated through western Tennessee to northern Mississippi. On March 29, 1862, the Army of Central Kentucky was merged into the Army of Mississippi in preparation for the Battle of Shiloh. Under the command of Lieutenant Colonel Archibald K. Patton, the 15th Arkansas saw its first combat at the Battle of Shiloh, April 6–7, 1862, where it suffered heavy casualties in driving back Sherman's division of Union troops.