Kenny, I just visited the Confederate Cemetery at Resaca. all four of your men have markers, however that battle was on May 14-15, 1864. If there date of death (5-9-1864) is accurate they were killed during the action at Dalton and retreat to Resaca on that date.
Also the marker for McGill is broken off and the only words remaining are "Regt. Miss.". In addition Baines is spelled "Baynes" on the marker.
One man's marker reads, "Corp. J. R. 37th Miss." I assume that is Richmond. I have photos. W.G. McGill is intact. Hope this helps.