Here is some information that may pertain to your great grandfather and where he is buried follow the links below.
He may have been with the CSA Tenn 23rd infantry all the other documents show he filled for pension in Texas which also show him in the Tenn 23rd Infantry.
Dear Ms. Briscoe,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the series Carded Records Showing Military Service of Soldiers Who Fought in Confederate Organizations in the War Department Collection of Confederate Records (Record Group 109) that may include a file for James Alfred Wheeler. To request a copy of his non-digitized service record, please download the NATF Form 86, fill it out to the best of your knowledge, and mail the completed forms to the address listed on the form. For more information about the ordering process see Requesting Copies of Older (pre-WWI) Military Service Records. For more information about these records, you may contact the National Archives at Washington, DC - Textual Reference (RDT1) at firstname.lastname@example.org.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT1. Also, please note that the National Archives and Records Administration (NARA) has suspended reproduction and digitization services until further notice due to COVID-19. Orders will not be serviced until operations can resume safely. Once operations resume, document reproduction requests will be filled in the order in which they were received. We apologize for this inconvenience and appreciate your understanding and patience.
The Civil War Soldiers and Sailors System (CWSS) is a database containing information about the men who served in the Union and Confederate armies during the Civil War. Other information on the site includes histories of Union and Confederate regiments, links to descriptions of significant battles, and selected lists of prisoner-of-war records and cemetery records, which will be amended over time. The CWSS is a cooperative effort between the National Park Service and several public and private partners whose goal is to increase Americans' understanding of this decisive era in American history by making information about it widely accessible.
We searched the CWSS and the only listing for a James Wheeler we located that served in a Texas unit was assigned to the 16th Regiment, Texas Cavalry (Fitzhugh's). Please see Wheeler, James A. for the listing.
For Confederate volunteer units raised by the State of Texas, there may be additional information in the custody of the Texas State Library and Archives Commission. Also, the staff of some Civil War related museums and Texas State Historical Association may be able to assist you with your research.
We hope this is helpful. Best of luck with your family research!