If he was wounded at Bay Minette, I would suspect that if he was hospitalized, it would have been just south on the Bay at the Point Clear Grand Hotel Hospital. Their records were destroyed by fire some years after the war. About 15 years ago, three or more burial trenches were discovered and work to determine those buried commenced. I suggest you locate the nearest Sons of Confederate Veteran Camp for information on what they have found.

I am far and away from the Washington, DC National Archives living next to Reno, NV.

Samuel Herring, Private, Company E, Steede's Battalion, Mississippi Cavalry,* enlisted May 14, 1862 in Perry County by Capt. Evans, transferred from Company C, March 1, 1863, recorded present on the end of year, 1863 muster roll, no further records

Note: I do not find a record of him in the 9th Mississippi Cavalry.

* The 17th Battalion Mississippi Cavalry (also known as Steede's Battalion Mississippi Cavalry and as the Lovell Rangers) was organized about May, 1862, with six companies which were consolidated in August, 1863, into four companies. This battalion was consolidated, December 24, 1863, with the 17th Battalion Tennessee Cavalry and Capt. J. A. Jennings' Independent Company Mississippi Cavalry to form the 9th Regiment Mississippi Cavalry, this company becoming Company C, of that regiment.

M269: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Mississippi

..........

Record of Events for Seventeenth Battalion, Mississippi Cavalry
(Steede's Battalion),
May 1862-December 1863

Company E

Stationed at Scotts Ferry, Madison County, Mississippi, October
31, 1862-June 30, 1863.

Stationed at Brandon, Mississippi, November-December 1863.

..........

9th Mississippi Cavalry (Miller’s)

(formerly 17th Battalion Mississippi Cavalry, aka Steede’s Battalion Mounted Partisan Rangers, & aka the Lovell Rangers)
http://www.mississippiscv.org/MS_Units/9th_MS_CAV.htm