I have been researching some of this info. I found a letter who stated there was a soldier buried in Saltillo MS near the church. The only record of a church that I found in Saltillo is of a Presbyterian church founded in 1850. I know churched can move their physical meeting places but the Presbyterian one is very close to the Old Natchez Trace which has 13 unknown CSA graves. These could be the burial referenced in the letter. but the individual was sick themselves and did not attend the burial so it could have been just close to the church in reference. It seems there was a field hospital in Tupelo which is not far from Saltillo. And there was Measles and Mumps going thru the camps. Here is a link to the letter: https://vmi.contentdm.oclc.org/digital/collection/p15821coll11/id/1339/