Muster rolls for many units were lost and never recovered post war. In this case, he was not present at muster and no one could account for him. Thus, the mustering officer had no recourse but to record him as AWOL. He must have later reported to his unit, only to be recorded at his next muster, as sick in camp.

We can only assume he returned to his unit to serve honorably.

I cannot locate your Cornelius Dowd Deaton, he is not listed with the 35th Cavalry.

George Martin