I have since found someone looking for info on this same family. They are descendents of Nils Clausen and and Sophie Amalie Cypriansen but I have not been able to contact them.
I would love to get in contact them or other cousins still living in Norway to find more about the family who stayed behind and if my great grand-parents wrote them letters.
It appears Nils had 4 sons John, Sverre, Svend and Albert.
Nils later remarried Elise Berntine Ananiassen and it appears they had more children, Ingrid Clausen, Karl Johan Clausen and Edit Marie Clausen.
Nils is a brother to Carl, my great grand-father who came to the U.S. If someone posted the following post on another website let me know:
My great-great grandparents named Nils Clausen (born 20.12.1861, Norderhov, Ringerike, baptized Norderhov Church 09/03/1862 - parents Svend Clausen and Andrine Nilsdatter) and Sophie Amalie Cypriansen (born 15.01.1856, Horten, Horten baptized Church 03/02/1856 - Parents Johan Cypriansen and Olava Power). Nils and Sophie's son John was my great grandfather. Moreover, they had sons Sverre, Svend and Albert