Are you looking for a Samuel Nilsen who was born about 1853? Without knowing some vital dates a search can be impossible.

The 1920 US census shows a Samuel N. Overbo and wife "Esabella" in Ramsey Co., North Dakota. Is this your family? At least approximate birth information is given in US censuses and usually some info about immigration year.

A Samuel Nilsen was born about 1853 or 1854 in Jølster district of Sogn og Fjordane, Norway. Sogn og Fjordane is the county/fylke immediately north of Hordaland.
Samuel Nilsen is found with family in the 1865 Norwegian census. The family lives on a farm there called "Øvrebø" or "Bø - øvre".
http://www.rhd.uit.no/folketellinger/ftliste_e.aspx?ft=1865&...

In the emigration database of persons leaving from the city/port of Bergen, Samuel leaves with his wife in 1883 --
http://digitalarkivet.uib.no/cgi-win/webcens.exe?slag=visbas...