Hilmar Sorensen - Buksnes- 1900

My maternal grandfather was Hilmar Sorensen, born July 7, 1884 in Buksnes, Vestvagoy, Nordland. I have the 1900 census information on the domicile of Orgotten. He was the 4th of 6 children. His father was Soren M. Nilssen and mother was Marta Karlsdatter. In the early 1900's he left on a ship for America (I do not know what boat) and never returned to Norway or the Lofoten Islands. (but he loved dried whitefish all of his life!) How do I go about finding out about his relatives in Norway? We do not think any others emigrated to the US. Hilmar was a carpenter in Brooklyn, NY and died in 1957.