Hi Eileen and Roger,
I looks as if this is your ancestors in the 1880 census
All persons in the household
thisted, Refs, Ydby, Dover By Ydby Sogn, , En Gaard, 173, FT-1880
Name: Age: Marital status: Occupation in household: Occupation: Birth place:
Niels Peter Christensen Krogh 42 Gift Husfader Gaardeier Vestervig Sogn Thisted Amt
Ane Katrine Pedersen 38 Gift hans Hustru her i Sognet
Else Marie Christensen 3 Ugift }deres Born Do [her i Sognet]
Christen Krogh Christensen 1 Ugift }deres Born Do [her i Sogn
The birth of Christen Krog Christensen on 9 Jul 1878 to Niels Peder Christensen and Ane Cathrine Pedersen can be found in Ydby, Refs, Thisted, opslag 40 nr 11. It seems that he changed his name to Christen Christensen Krog in 1905.
If this looks like you ancestor please let me know and I will see what else I can find.
North Carolina, USA