The bad news here is also my motivation to learn more about family history: I thought I knew the story but now I'm not so sure. The Hakan Andersen Book would set me straight, but it resides at my parents' house (so mom, you may have to set me straight). Here's what I think happened.
Hakan (or Hogan) (or Haakan) (or about ten variations) crossed the plains as a young-but-not-that-young convert to the Church. When he arrived in Salt Lake, as a strong healthy man, he was asked to go back and help others across the plains. There he met a girl and fell in love with her...however, she was sick or something and died. I think. But the good news is that this girl had a friend! And she was Cecelia. And Hakan and Cecelia got married and had a family and moved to Idaho.
This is the lineage: Hakan and Cecelia had a daughter named Hannah, whose son Hakan Ostlin went by Ostlin and was my paternal grandma Ada's father. So in reverse, Me/Dave/Ada/Ostlin/Hannah/Hakan & Cecelia.
|Hakan & Cecelia's family|
|Hannah Andersen, presumably before she married John Alfred Hanson|
So here is what Familysearch.org taught me. Hakan crossed in 1859 with the George Rowley Company. Cecelia Swenson crossed in 1863 with an Unknown Company. They were both from Sweden (but I already knew that one).
You can find your own Pioneer Ancestors on Familysearch.org too, I think. Do it! It's cool.