May 17 Organized at under Colonel Thomas P. August

Assigned to McLaw’s Brigade

July 1
Battle of Malvern Hill

Colonel August was wounded and would be assigned to the Bureau of Conscription

September Maryland Campaign. Assigned to Semmes’ Brigade, McLaws Division.
September 14
Battle of South Mountain

Ordered in the evening to proceed with the 32nd Virginia Regiment and two pieces of Manly’s battery to the top of South Mountain at Crampton’s Gap to watch for and report any advance of the enemy in that direction.

September 17
Battle of Sharpsburg (Antietam)  

The regiment was commanded by Captain Emmet M. Morrison of Company C (VMI 1861) and brought 14 officers and 114 men to the field. Captain Morrison was wounded and captured, and Captain Edward J. Willis took over the regiment. the regiment lost 1 officer and 10 enlisted men killed and 6 officers and 58 enlisted men wounded.

From the War Department marker for Semmes’ Brigade on the Antietam battlefield:

Semmes Brigade reached the western suburbs of Sharpsburg at sunrise of the 17th and halted until nearly 9 A.M., when it advanced across the fields, in support of Stuart’s Cavalry, north and west of Hauser’s house. In the general advance of McLaws’ Division it was on the left of the line, and encountered the enemy in the northern part of the West Woods, forcing them to retire beyond the Nicodemus house.

Near this point its advance was checked by the Federal Artillery east of the Hagerstown Road. After severe losses it was withdrawn and placed as a reserve to Barksdale’s Brigade, in the western edge of the West Woods, where it remained until the night of the 18th when it recrossed the Potomac.

From the Official Report of Captain Willis on the 15th Virginia at Antietam:

This regiment went into action under the command of Captain E. M. Morrison, of Company C, the field officers being all absent. This regiment, as all others of the brigade, was very much worn down by hard marches, loss of sleep, and scanty rations, rendering officers and men unfit for the work before them. Straggling, occasioned by sickness, sore feet, and faint-heartedness, reduced the effective strength of the regiment when presented before the enemy to 14 officers and 114 men. This strength was indeed effective, as their work proved, standing shoulder to shoulder with their brave comrades of the brigade. They showed by their unerring aim and eagerness for the charge their willingness and ability to go wherever they might be commanded by their gallant leader, General Semmes, whose bravery on this occasion commanded unwounded admiration and confidence. This regiment occupied a position in the left wing of the brigade, which was on the extreme left wing of the army. They united with great spirit in the charge to which they were ordered, and bore their part in driving from a strong position a greatly superior number of the enemy, forcing them back with great slaughter nearly 1 mile, from which they never recovered. The regiment held its position until some time after the musketry firing of the enemy had ceased, when they were withdrawn with the brigade to replenish their ammunition, which was well nigh exhausted.

In this battle the Fifteenth Virginia Regiment sustained a greater loss than any regiment of the brigade or army, as far as information has been received. Of the officers (14 in number) who entered the fight, 1 (Captain [A. V.] England, Company D) was killed, and 6 (Captain [E. M.] Morrison, commanding the regiment; Second Lieutenant Bumpass, Company C; Second Lieutenants [J. K.] Fussell and [J. H.] Allen, Company G; Second Lieutenant Berry, Company H, and First Lieutenant [G. P.] Haw, Company I) were wounded. Of the non-commissioned officers and privates, 10 were killed and 58 wounded.

So determined was the courage evinced by all the officers and men who bore a part in this fight, that it would be invidious to call names. The unusual loss, from our ranks, of men and officers has naturally cast a feeling of depression over those who now constitute the regiment.

Soon after the engagement commenced, Captain Morrison, who was bearing himself with great bravery, was seriously wounded by a shot through the right breast, which devolved the command upon Captain E. J. Willis, of Company A. The color-bearer (P. H. Hall, of Company A) having been wounded, the colors were placed in the hands of Captain Willis by Sergt. Major W. H. Briggs, who was severely wounded while bearing Captain Morrison from the field. Having rallied the regiment for the charge, Captain Willis placed the colors in the hands of R. W. Taylor, of Company B, one of the color supporters, who bore them gallantly through the engagement.

August Captain Morrison, in a Federal prisoner of war camp, was promoted to major.
November 26 Transfered to Corse’s Brigade, Pickett’s Division,  1st Corps.
January 24 Major Morrison, still a prisoner, was promoted to lieutenant colonel.
April Lieutenant Colonel Morrison was exchanged and returned to the regiment.
Suffolk Campaign
July On detatched duty and did not participate in the Gettysburg Campaign
October 21 Captain Willis was detached for medical reasons to Confederate States Barracks (Hospital), Richmond
April 6
Battle of Sayler’s Creek

Most of the regiment was captured, including Lieutenant Colonel Morrison.