Brick wall- Spouses of my grandfather William P Olson.

I have confirmed my Grandfather William P Olson's Birth in Habol Alvsborg  1853 thanks to help from Yvonne.  I was told he emigrated to the US in 1874 or 1879. I believe He is in the 1880 US census in Hennepin County Minnesota as a William is shown as a stone Mason born 1858.  There also was a Peter Olson age 22 in a 1875 Minn. State Census but no occupation is shown. In 1885 Colorado state census Jefferson county he is shown age 30 souse Lena 29 daughter jenny age one , both parents born in Sweden,  i have a Marriage licence showing William Olsen marrying a Lena bergstrom 10 Feb 1883 in a swedish Evangelical Lutheran Church . They had  3 Children   Jenny  1884-1907  Laura 1886, and Caroline (Sally)  Nov 1887.   Lena , Shown as Caroline  in a state death record with no details other thana date intered of 12 /30/1887.    William  then shown in a Marriage licence of May 19 1888   as Peter William olson marries Josehine M Bergstrom  at a Swedish Methodist Chuch . Based on a letter to my mother it appears that Josehine is a sister of the deceased Caroline.  Josephine dies 8 Oct 1912 after having 10 children including my mother.  The 1900 census shows Josehine  emigrated in 1887 which makes scene as my grandmother had cancer & they knew she was going to die.  I have a death certificate for Josephine  with her husband as informant, that shows her father as Leonard  Bergstrom and her mother also named Josephine.  I have not been ablle to find any emigration records or records of them in Ancestry or Family search....I also dont know why the Bergstroms arent following the Swedish naming procedure. I recently did a Mito dna which gave me a o difference match wit a woman whose ancestors come from same area as my grand father   ( Steneby, 1 in Habol etc,) She couldnot  nt find any matches .I do not know what to try next    Thanks     W  Michael Schummer