The family sailed to America in 1864 on the ship Monarch of the Sea. The ship manifest shows his name as "Nils Nilsson."
Pehr and his wife were listed on the company manifest under the surname of 'Nilsen." Their two children Nils and Johanna were listed under the surname of "Pehrsen." Their son Soren was listed under the surname of "Enstrom."
More research is needed to confirm Nils's date of death.