There were several confederate hospitals in the Griffin Ga. area with their associated cemeteries. Old Oak Hill and Stonewall Jackson cemeteries are 2 of several that have confederate vets from TN and MO in them.
http://cityofgriffin.com/Portals/1/Documents/Newsletter/turn.js-master/demos/cemetery%20book/pages/cemetery%20book%20final%20draft.pdf
The battle of New Hope Church, Ga. was May 25 -26 1864 early in the Atlanta Campaign. Though a Confederate victory, they shortly thereafter vacated the field to Sherman. I suspect he was wounded in May, evacuated to the hospital in Griffin which was receiving the majority of the Atlanta casualties and died last week of August 1864.
https://www.civilwar.org/learn/galleries/new-hope-church 1st and 3rd MO Cav (consolidated) were there.
John R