Hovland Ancestry

I have been trying to find my ggrandparents who came from Norway. GGrandfather: Lars/Lewis Hovland born Oct. 30, 1854 in Hadeland, Oppland, Norway. GGrandmother: Mathilda Dahltorp born Oct. 8, 1865 in Fredrikstad, Ostfold, Norway. They were married in the USA in 1900. I have been unable to find out anything else about them such as their parents, when they immigrated, etc. Can anyone help me? Please? Thank you. Judy Koenig[:)]