John F. Hanne was a German emigrant to New York. His son is Frank Hanne (wife Addie) born 1855 died 1923 who is also buried in Denlow Cemetery. Frank's death certificate is on file with SOS at:
Frank and Addie are listed in the Douglas County Census in 1910 and 1920 where Frank lists his father as being born at sea...
There are numerous sound alike names for Hanne e.g. Hoehn, Hanney, Hanna, etc...
I find no specific record for Civil War service for John F. Hanne using the stated spelling.
John R.