Hi, Renee.
Yes, I suspect his brother or another comrade in his company saved the diary for loved ones back home. A headboard was inscribed with initials to identify the burial spot, with intentions of disinterring at a later date. Since Chickamauga was a Confederate victory and the Union had many casualties and burials to tend to, there was probably too little time to carve or inscribe a more complete name. In many cases the headboards had become weather-worn and hard to read by the time of the disinterring and reburial.
Best Regards,
Greg C. White