I need help finding my grandpa's ancestry?

My mom's real dad ran away when she was a baby. My mom's real dad would be my grandpa. I want to know his ancestry really bad. I have been researching him on the internet and I can't find any results. His name is Jack Hallison. he was born in West Virginia in 1946 I think but I'm not sure where in West Virginia he was born in. I thought his last name hallison would be scandinavian. I talked to my Danish penpal that lives over in Denmark and she said the last name Hallison is most likely going to originate over from Norway or Sweden or possibly England.