Neep help Completely Lost... Petersen & Hansen NY

Hello, I've been searching for awhile now about my fiancé's family in Brooklyn New York. Her Great Grandparents both immigrated from Norway to New York somtime around 1890s-1900. Both were unmarried at the time. Peter Petersen was born 21 Mar 1875 in Norway. I have no clue where to find out what town he was from. I've checked naturlization papers & could not find him anywhere. He was living in Brooklyn from 1898 to at least 1940. I cannot find where or when he died either. I need to find out what his parents names were also & any/all info about him. His wife, who he married on 24 May 1902 in Brooklyn, was - Hansine Hansen. Another one that I cannot find anything on. She was born in 1883 & died in 1935. Together they had 6 children - Lydia, Joseph, James, Clarence, Hazel & Lois. Any help would be GREATLY appreciated. I do have some photos of both of them but unfortunatly, that is the most info anyone in the family has about them. My fiance's father passed away many years ago & she never had the opportunity to discuss family history with him. She was only 14 when he died. Thank you very much in advance. John Schalcosky [email hidden]