[13][14] Soon after being organized, the regiment was ordered to Mississippi, along with the rest of General Earl Van Dorn's Army of the West.

The regiment was immediately ordered with the remainder of Rust's Brigade to Fort Pillow, approximately 50 miles (80 km) north of Memphis.

Measles broke out among the men almost immediately, and by the time the regiment arrived at its assigned station at Fort Pillow, near Fulton, Tennessee, it had become a full-fledged epidemic.

The extremely muddy conditions and very poor quality of the water supply at Fort Pillow undoubtedly contributed to these losses.

[18] All twelve-month regiments had to re-muster and enlist for two additional years or the duration of the war; a new election of officers was ordered; and men who were exempted from service by age or other reasons under the Conscription Act were allowed to take a discharge and go home.

Forming in a line of battle, the 18th Arkansas made a breath-taking charge under an enfilading fire from the entrenched Federal troops.

Climbing through and over fallen timber, the 18th Arkansas relentlessly advanced right up to the enemy's breastworks, where the withering fire melted the regiment away.

Sorely depleted after the events of April to October 1862, the 18th Arkansas underwent several field consolidations with other units while assigned to the Department of Mississippi and East Louisiana.

Field consolidations were considered to be temporary, and the component regiments continued to maintain separate muster rolls.

Two audacious lieutenants of Company K, however, James W. Hellums and George P. Atkins, escaped from their captors by jumping from the Union transport into the muddy water of the Mississippi River between Napoleon and Helena, swam ashore, and eventually reached the Confederate lines.

[22] As part of Dockery's Brigade, remnants of the regiment saw action at the Battles of Prairie D'Ane,[23] Marks' Mills,[24] and Jenkins Ferry.

[28][29][30] On 22 January 1865, Major General Churchill was ordered to move his division to Minden, Louisiana, and occupy winter quarters.

[31] Union commanders in the Department of the Gulf reported on March 20, 1865 that General McNair's brigade was located at Minden, Louisiana, with the rest of Churchill's Division.