Date of birth calculated from tombstone inscription.
First husband of Mary Austin.
1st Lt. Co. A. 118th Regt. Ill. Vol.
Killed at the Battle of Champion Hills.
Both a family tombstone and a government issued military marker were placed at Alton Cemetery for Thomas.
There is also a military tombstone for him at Vicksburg National Cemetery, Vicksburg, Warren County, Mississippi.
Best guess: the first one was issued not too long after he was killed and the one at Vicksburg was placed after his actual remains (or what the government thought were his actual remains) were reinterred there.