Looking at the records you cited for Joel A McPherson, they clearly show that he was absent, sick in hospital, Sept - Dec 1862. He was present through Feb 28, 1863, with no roll on file for March - April 1863. He was absent on daily duty, Apr 30 - Oct 31, 1863. Since he was not paroled at Vicksburg MS, Joel A McPherson must not have beeen with the garrison of that city. The other record you cited reads, "Non-paroled - Detailed provost guard." This means he was on detail, serving as a provost guard before, during and after the Vicksburg Campaign. Evidently he served some place outside of the immediate area covered during the Vicksburg Campaign, perhaps at Meridian or Columbus MS.

If this man died during the war, date of death must have been after Dec 31, 1863.

I can review the other McPherson records if you wish.