Andersen from Gran, Hadeland

I am looking for information about 3 siblings from Gran, Hadeland: Christen Andersen born 2. nov 1832, married Marthe Amundsdatter in 1863 and left with her and his parents in law to USA in 1867. Ingeborg Andersen born 14. june 1841, married Lars Larsen Egge 30. jan 1868 and left with him and their daughter Rilda born 1868, to USA in 1870. Karen Andersen born 30. june 1850 and emigrated to USA sometime after 16. april 1870 - may be with the bark "Colonist" from Drammen 10. may 1870. What happend to them in America? I have a little information about Christen and Ingeborg: They settled in Fillmore county, Minnesota. I also belive there is information about them in something called the Rowberg files. Someone with access and kindness [:D] who can send me that information? About Karen I know nothing from USA.