Could you give me the sources you researched? Is there some comprehensive list of Confederate dead at Chickamauga? All I have is the Combined Service Record of Joseph Phipps which shows him as a Corporal in Co I of the 18th Texas Cavalry. The Sept and Oct Company Muster Roll indicated he was killed in battle Sept 22 at Chickamauga. This is why I had asked about the source of the NARA Combined Service Records.
I have also subsequently found a Phipps from Texas (first name unknown) buried in Marietta Confederate Cemetery in Georgia. Research indicates many Confederate dead were removed from the Chickamauga battlefield around 1867 and reinterred at Marietta. I have no way to confirm this is my Phipps.