There are several Oleson families living on Huron Street in Chicago in 1880. John, Louis and Adolph are brothers. Oliver Oleson and his wife and children appear to be living in the same house, so Oliver could be a 4th brother. However, John appears to be from Østfold, and I can't find Oliver's birth there.

This link will only work if you use ancestry.com:

http://search.ancestry.com/iexec?htx=View&r=an&dbid=...

Here is Oliver and his family:

House #206, family #471

Oleson, Oliver, 39, machinist, born in Norway
Oleson, Sinna, 30, wife, born Norway
Oleson, Oscar, 4, born Illinois
Oleson, Anton, 2, born Illinois

Directly above them:

House #206, family #470

Oleson, John, 34, tanner, born Norway
Oleson, Emily, 38, wife, born Norway
Oleson, Ellen, 5, daughter, born Illinois
Oleson, Hannah, 3, daughter, born Illinois
Oleson, Raganor, 4/12, daughter, born Illinois
Oleson, Louis, 30, brother, wood turner, born Norway
Oleson, Adolph, 22, brother, carpenter, born Norway

John Oleson immigrated in 1871. His wife Emilie came in 1872 and they married in Chicago 28 Dec 1872. I believe they knew each other in Norway. Emilie (Evensen) was born in Trygstad, Østfold, so John probably came from Østfold also.

I can't find anything that proves that Oliver was a brother of John, Louis and Adolph.... but it sure looks possible.