Rognholt Farm in Nordre Land, Oppland

I am seeking any information regarding my g-grandfather who was born Jens Nelson (Nilsen) in 1854. He left Norway around 1871 for South America but the ship dropped all passengers in Ireland where he remained for 3 years. He reportably made arrangements with a banker from Iowa and worked 3 years to pay his passage. He eventually moved to Wisconsin and took the Rognholt farm name as his last name. If anyone has any information regarding him or the Rognholt farm, it would be greatly appreciated. Thanks! Mitch Rognholt