As the author of Peculiar Honor, I examined every compiled service record for the 28th Texas. Many (in fact, most) of the service records are incomplete for this regiment. Your situation is extremely common--most Confederate records are incomplete. Oftentimes, Confederate pension records yield more information about a soldier's service than their compiled service record. Have you searched the Texas Archives for a pension record for William Woodson Wright or his widow? The website address is: www.tsl.state.tx.us/arc/pensions/index.html
I just searched this website and located Adeline Wright--her husband is listed as William Woodson Wright. If you haven't already done so, go to the above website and enter Adeline's or William's name. You will be given an application number--you use this number to request a copy of the pension application from the Texas State Archives. Don't be concerned about the application being in Adeline's name--the application may still contain valuable information about your ancestor's service record. Good luck!