Capt. Mangum enrolled as a 1st Lt., Co. B, 2nd Texas Infantry, August 7, 1861 at Camp Kyle, Texas, age 29, August 8, 1862, he was transferred to Genl J. C. Moore's staff as Acting Adjutant General.
I searched the ORs and find no further information after the May 26, 1863 report.
2nd Regiment, Texas Infantry
2nd Infantry Regiment [also called 2nd Texas Sharpshooters] was organized by J.C. Moore during the summer of 1861. Many of the men were from Houston and Galveston. After serving in the Department of Texas, it moved east of the Mississippi River and fought at Shiloh, Corinth, and Hatchie Bridge. Later it was assigned to Moore's Brigade, Department of Mississippi and East Louisiana. Under this command it was active at Snyder's Bluff and surrendered with the forces at Vicksburg on July 4, 1863. Its casualties during the campaign were 38 killed, 73 wounded, 15 missing, and 11 died of sickness of the 468 engaged. After being exchanged, only 29 were present as the majority of the men had returned to Texas. Later it was reorganized and in April, 1864, stationed at Galveston Island, there were 18 officers and 190 men fit for duty. That summer it suffered from a yellow fever epidemic but went on to participate in the defense of Galveston. In April, 1865, it contained 395 effectives but disbanded before the surrender on June 2. The field officers were Colonels Noble L. McGinnis, John C. Moore, William P. Rogers, and Ashbel Smith; Lieutenant Colonels William C. Timmins and J.F. Ward; and Majors Xavier B. Debray, George W.L. Fly, and Hal. G. Runnels.
FEBRUARY 24, 1863.--Capture of the Indianola.
No. 4.--Report of Maj. J. L Brent, C. S. Army.
On taking possession, we found our prize rapidly making water, which we could not arrest. Seeing that she would sink, I did not wish that this should take place on the western side of the river, and therefore made fast to her with two of the steamers, and towed her over the river, when she sank in the water up to her gun deck, thus losing to us the greater part of the valuable stores that were in her hold. Captain [James W.] Mangum, assistant adjutant-general of Brigadier-General [J. C.] Moore, being in Alexandria, accompanied the expedition as a volunteer and acted as my adjutant. He comported himself gallantly under fire, and throughout the expedition rendered me valuable service. OR V24, Pt.2, p. 368
HEADQUARTERS FORNEY'S DIVISION, May 26, 1863.
Maj. R. W. MEMMINGER, Assistant Adjutant-General:
MAJOR: I have the honor to send you, by Captain [James W.] Mangum, of General Moore's staff, a battle-flag, brought in last night by Private Stewart, Second Texas Regiment, and to inclose the accompanying notes from General Moore and Colonel Smith. I respectfully recommend that the request therein contained be granted.
I am, major, very respectfully, your obedient servant,
JNO. H. FORNEY.
OR V24 Pt. 3, p. 921
Organization of the Confederate Army of Vicksburg, Lieut. Gen. John C. Pemberton commanding, July 4, 1863.(*)
Maj. Gen. JOHN H. FORNEY.
Brig. Gen. Louis HEBERT.
3d Louisiana, Maj. David Pierson.
2lst Louisiana, Lieut. Col. J. T. Plattsmier.
36th Mississippi, Col. W. W. Witherspoon.
37th Mississippi, Col. O. S. Holland.
38th Mississippi, Capt. D. B. Seal.
43d Mississippi, Col. Richard Harrison.
7th Mississippi Battalion, Capt. A.M. Dozier.
2d Alabama Artillery Battalion, Company C, Lieut. John R. Sclater.
Appeal (Arkansas) Battery, Lieut. R. N. Cotten.
Brig. Gen. JOHN C. MOORE.
37th Alabama, Col. J. F. Dowdell.
40th Alabama, Col. John H. Higley.
42d Alabama, Col. John W. Portis.
1st Mississippi Light Artillery,(*) Col. William T. Withers.
35th Mississippi, Lieut. Col. C. R. Jordan.
40th Mississippi, Col. W. B. Colbert.
2d Texas, Col. Ashbel Smith.
Alabama battery, Capt H. H. Sengstak.
Pointe Coupee (Louisiana) Artillery, Company B, Capt. William A. Davidson