Joel,

The best way to know what happened to your grandfather would to read his records. They may tell of what battles he was at or if he was ill or wounded etc.
You can get copies at this site, I have used it and the folks are fast and do a great job.

http://history-sites.com/research/index.html

Here is a little info. for you.

James W. B. Reynolds (First_Last)
Regiment Name Griffin's Batt'n Texas Infantry
Side Confederate
Company B
Soldier's Rank_In Corporal
Soldier's Rank_Out Private
Alternate Name
Notes

CONFEDERATE TEXAS TROOPS

Griffin's Battalion, Texas Infantry (Griffin's Regiment) (21st Infantry)

Griffin's Infantry Battalion was assembled during the early summer of 1862 with six companies. The unit served in the Trans-Mississippi Department along the Texas coast and at Galveston, then in November, 1864, merged into the 21st Texas Infantry Regiment (with the 11th Cavalry and Infantry Battalion). The field officers were Lieutenant Colonel William H. Griffin and Major H. A. Hamner.

Griffin's Battalion, Texas Infantry (Griffin's Regiment) (21st Infantry)

Battles of Griffin's Battalion:

Galveston Island - January 1, 1863
Sabine Pass - (Detachment)-April 18, 1863
Sabine Pass - Companies D&F - September 8, 1863
Calcasieu Pass - May 6, 1864

Surrendered by General E. K. Smith commanding Trans-Mississippi Department, on May 26th 1865.

Reynolds men listed in the 21st. More kin ????

No. Soldier Name Company Rank In Rank Out
1
Reynolds, James W. B.
B
Corporal
Private

2
Reynolds, Robert L.
A
Private
Private

3
Reynolds, Sylvester S.
A
Private
Private

I hope this helps you in some way,
Gary D. Bray