Alan,
Thanks for your reply. The only thing that I had to go on was at this website: http://files.usgwarchives.net/ga/upson/military/civilwar/k-5.txt which lists Gilbert,John----private August 1863 - Killed at Chickamauga, GA Sept. 19,1863. I don't know that his middle name was Wesley and there were more than one John Gilberts. Will have to keep digging.
Martha