Hermand (Herman) Olson

Berthe Knutsdtr Odde b. 28 Jun 1830 Torpen, Norderland, Norway widow of Ole Haavelsen b. 11 Dec 1819 d.10 Jan 1864 Aasgaard, Stange, Hedemarken, Norway. They were married 12 Mar 1855. I believe she emg. to America 1873. She came with children: Hermand Olson b. 14 Mar 1856 Loiten Hedemarken, Norway Anne Olsdtr b. 11 Nov 1857Loiten Hedemarken, Norway Christian Olson b. 18 Sep 1859Loiten Hedemarken, Norway Karen Olsdtr b. 12 Dec 1861Loiten Hedemarken, Norway Ole Andrew Olson b. 13 Jan 1864Loiten Hedemarken, Norway Hermand (Herman) filed a letter of intention in Allamakee Co., Iowa on 23 Feb 1880. All siblings later changed their last name to Olswold. I know he later became a homesteader in Culberson, NE. Are there any previous family records on this family and is it known the ship they came over on and the port of entry. Any information would be greatly appreciated. Gene (Docbgood)