The 13th Alabama served in the East with Lee. Here is a report of the Tupelo scene from the 33rd Missouri, USA. They believed the flag was that of the 6th Mississipp, CSA. However, I do not believe this regiment was at Tupelo. Stawling had his leg amputated long before this engagement and I do not believe he saw further service.
Report of Lieut. Col. William H. Heath, Thirty-third Missouri Infantry.
HDQRS. THIRTY-THIRD MISSOURI VOLUNTEERS,
La Grange, Tenn., July 21, 1864.
SIR: I have the honor to make the following report of the part taken by
the Thirty-third Missouri Infantry in the skirmish of the 13th instant
and the battles of the 14th and 15th instant, at and near Tupelo, Miss. . . . . .
The enemy's last line was destroyed, and he retreat in the greatest confusion, leaving his dead
and wounded on the field. In this charge Capt. William J. McKee,
commanding Company D, was ordered to deploy his company as
skirmishers to cover a gap left between the Twelfth Iowa and
Thirty-third Missouri, and came upon a party of the enemy's
sharpshooters, whom he charged and drove from cover, killing and wounding several of them,
and capturing a rebel color (supposed to have belonged to the Sixth
Mississippi), which the enemy were endeavoring to recover from the
hand of their dead color bearer.
http://www.civilwardata.com/active/hdsquery.dll?RegimentHistory?3238&U