Holgerson, Dirk the Norseman

I am a decendent of Dirk Holkerson whose surname became Son of Folkert who then became Folkerson - then Fulkerson.I have a great grandfather who is John Fulkerson.We have a son named John Mark.My grandfather was William Richard Fulkerson and my father was William Vernon.My wife have done all the research on the family.My ancestors settled in Grayson and Nelson Counties in Kentucky.