Find A Grave Memorial 22835373 includes a gravestone photo with this inscription:
B. F. ERVIN
2ND IND CAV
This seems to suggest that B. F. Ervin served in the 2nd Indiana Cavalry Regiment; however, I cannot find anyone with the last name "Ervin", "Irvin", "Erwin", or "Irwin" in the roster for the regiment.
Why wouldn't he be listed in the roster, and where can his military record be found? I believe him to be Benjamin Franklin Ervin, b.c. 1838 in Hartford City, Blackford, Indiana.