I am a Koler (ne: Kjoller) an American citizen permenantly living in Australia who recently received from a relative gyneological tracing of my grand-father, Charles (Kjoller) Koler of North Dakota (born in Chicago, Ill.)
Found out from Andreas Kjoller of Denmark that most all Kjollers originate from Bornholm.
Hope you have had success with your research and tracing. I need help too. Oh, by the way - this is authentic, my grand-father was a marshal in a rough & ready town in north dakota territory.