John S. Marmaduke was assigned as commander of the 1st Arkansas Infantry Battalion and promoted to lieutenant-colonel on August 1, 1861.

On January 1, 1862, the unit was formally designated as a regiment, the 18th Arkansas Infantry, and Marmaduke was promoted to colonel.

On January 31, 1862, the regiment was redesignated as the 3rd Confederate Infantry because it contained units from multiple states.

[4][5] The 3rd Confederate Infantry was composed of the following companies:[6] Note: Companies I and K were composed primarily of suspected members of the so-called Arkansas Peace Society, who were arrested and sent to Little Rock by members of the 45th Arkansas Militia Regiment, where they were given the choice of Confederate service or imprisonment.

[6][9] Assigned to Hindman's Brigade, Hardee's Division in the Army of Central Kentucky from December 1861 through January 1862.

At the battle of Shiloh the 3rd Confederate bore the guiding colors of Hindman's Brigade and captured the first prisoners of the day.

In the second day's battle he was wounded and disabled, and while in hospital was recommended for promotion to the rank of brigadier-general.

Colonel Marmaduke commanded his brigade of Arkansans during the Siege of Corinth, and later was ordered to the Department of the Trans-Mississippi.

[12] 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.

In the reorganization, Wood's Brigade, including the 3rd Confederate now under the command of Major John F. Cameron, was assigned to Cleburne's Division and fought in the Battle of Stones River.

SIR: I have the honor to make the following report of killed, wounded, missing, and prisoners belonging to the Third Confederate Regiment, together with the part taken by my command, in action at Murfreesborough December 31, 1862: My command took position on the left of the brigade on Tuesday, [December] 30, and remained on the field until the army fell back.

The brigade was ordered to charge the enemy, strongly posted in a skirt of timber some 500 yards distant, a corn-field intervening.

I withdrew my command under cover of a captured hospital, when I reorganized my regiment and rejoined my brigade.

With the aid of 50 straggles, I charged the fence, driving the enemy, capturing their colors and about 30 prisoners.

My command being much reduced, Gen. Wood honored me with a position on his staff during the fight of Thursday, Friday, and Saturday.

Seizing the standard, he rallied hundreds of panic-stricken men, thereby reforming our then thin ranks.

The consolidated 3rd/5th Confederate Infantry was assigned to the brigade of Brigadier General Lucius E. Polk in Cleburn's Division of the Army of Tennessee.

The right of the brigade, however, meeting with less resistance, pushed on, and getting on his flank he soon retired in confusion, leaving a 12-pounder James gun and a caisson, having set another on fire.

We remained in line during the night of the 19th, replenished our supply of ammunition, and were ready to move again at daylight.

When the attack was renewed we met the enemy at his works, which were located on the crest of a rise that commanded the space in front of it.

Failing as we did to drive the enemy from his position, and our ammunition being exhausted, we were ordered by Brig.-Gen. Polk to fall back.

His resistance here was, for long, as obstinate as in the morning; but we finally proved too much for him, and he took refuge behind his second line of works, about 200 yards to the rear of his first.

He made but a short stand here and then fled in confusion across the open field in rear, leaving many prisoners in our hands.

SIR: From a position behind what I learned to be Taylor's Ridge, covering the road and railroad bridge, the regiment advanced in line of battle some 300 or 400 yards to the summit of the hill.

Our sharpshooters encountered the enemy's, and immediately after he appeared in line of battle, making his way up the opposite steep.

Brown, senior officer present, until my arrival with a detachment of the regiment ordered to guard Shallow Ford Bridge.

[23] The 3rd Arkansas and the rest of Govan's Brigade were released and exchanged just in time to participate in General John B.

Brigade effective strength was approximately 550, plus or minus a dozen or so, so each battalion fielded around 100-110 rifles.

[27] On April 26, 1865, the 1st Arkansas Consolidated Infantry Regiment was present with the Army of Tennessee when it surrendered in Greensboro, North Carolina.

In his report dated September 10, 1864 Captain Toland Jones noted that "we captured the battle-flag of the Third Confederate Infantry Regiment inscribed with the names of seven different battles."