I think this Pvt. Alford F.Vance, Co C., 16th KY Cav. is the "A.F. Vance" bur. in Mound City, Illinois; all I'm saying is that the A.F. (Abner Field Vance) bn. KY, that I'm researching, was a son of a pro-southern father who "per other researchers, say was banished to Canada during War" for his pro-southern sentiment), and I think he likely is not the one buried in the National Cemetery in Illinois.

I did see some info from military records (can't locate just now) which gave an alternate name on "A. F. Vance" as .... "Chance" suggesting that perhaps the records were not clear as to the last name? But, there is an original card for the grave which give's "A.F. Vance's" Regiment and Company which corresponds to "Alford F. Vance" that you cited.

U.S. Veterans Gravesites, ca.1775-2006
about A F Vance
Name: A F Vance
Service Info.: PVT US ARMY CIVIL WAR
Death Date: 1 Feb 1864
Cemetery: Mound City National Cemetery - IL
Cemetery Address: Junction - Highway 37 & 51 Mound City, IL 62963
Buried At: Section D Site 2882