The 1st and 4th Missouri (Consolidated) and Cockrell's Missouri Brigade fought as a unit of the Confederate Army of Tennessee during the Atlanta Campaign from May to September 1864. During the campaign, the regiment was part of French's division of Major General Leonidas Polk's corps. Cockrell, now promoted to brigadier general, still commanded the brigade the regiment was in. Besides the 1st and 4th Missouri (Consolidated), Cockrell's brigade contained the 2nd and 6th Missouri (Consolidated), the 3rd and 5th Missouri (Consolidated), and the 1st and 3rd Missouri Cavalry (Consolidated). The regiment was engaged at the Battle of New Hope Church on May 25 and 26, where Colonel Riley was killed in action. Regimental command then passed to Hugh Garland, who was promoted to colonel on May 30.