Andreas,
The 1880 census might hold some clues for you. You can go to
familysearch.org and click on Search for ancestors in our vast records
collection
On the next screen, click on Census
On the next screen, select 1880 US Census
Type in the Last Name,
select Ohio from the Census State list, and wait for the counties to
load, then select Jackson.
Wait for the towns to load. You might want to select one of them, or try
all.
I find it helpful to enter as little information as possible, to allow
for variations in spellings, etc.
I didn't find any KNIGGE or PORTNER in Jackson Co.
You can try other combinations, such as no last name and then Prussia for
birthplace, or enter only Henry with no last name, etc.
Good luck!
Mona