Any Information on Ernest Rothaupt

I am looking for any information on Ernest Gottlieb Rothaupt born September 14, 1908 in Oslo, Norway. We came to US on Ship called Edam on April 6, 1926. He was legally admitted to Portland, Maine. He returned to Oslo, on a ship named Stravanger (Norwegian American Line) on February 7, 1927 to visit relations. I haven't been able to find any information of his arrival in United States. I am looking to see where his parents or siblings lived and worked, etc. Any information would be helpful. Thank you.