Clarissa , This search might take longer than I originally thought.
However don't give up ! You never know who has information
on your Great Grandfather, Sidney Ira Taylor. I reviewed some rosters of NE Mississippi
Units and neighboring Alabama Units & found a couple of long range possibilities.

After researching my CSA family military history for 10 years , I've learned that nothing
happens overnight, even if you go months without any new information, there is a good
chance someone will surprise you when you least expect it.