Nels Aamodt

My great-grandmother on my father's mother's side of the family was named Aslog Nielsen Aamodt. She was born in Oslo, Norway to Nels and Annie Aamodt in about 1847. She died in Wilmar, Minn. in 1927. She married Ole Christopherson and they lived in Benson, Minn. I am looking for her parents and where they came from in Norway and any information who their parents were. The 1880 US Census shows a Nils Aamodt living in Minneapolis, Minn with a wife Sara at 60 years old. That matches the birth information I have of Nels (Nils) being born in 1820. Any information anyone would have would be appreciated.