I don't think that anyone has ever compiled a list of the end of the war paroles at Vicksburg [technically at Big Black River]. I don't think that there is a list of those from Meridian, either.

There is an online listing of the paroles at Vicksburg from July 1863, when the city fell to the Union. Here is info from there:

SUMRALL, F.N. PVT 37TH MS INF Company D
SUMRALL, H.R. SGT 37TH MS INF Company D

http://www.nps.gov/vick/parole/csp_indx.htm

Company D was the Enterprise Tigers, raised in Clarke County, MS.

Company E was the Shubuta Guards, also raised in Clarke County, MS. So these were likely relatives to your man.