The only "William" I'm finding with a similarly spelled name is a:

Name: William Hollenback ,
Enlistment Date: 11 Feb 1864
Enlistment Place: Hillsdale, Michigan
Service Record:
Enlisted as a Private on 11 February 1864 at the age of 28.
Enlisted in 27th Infantry Regiment Michigan on 12 Feb 1864.

Jim Martin