You can find them on familysearch.org. Johan b. Aug 1840 Sweden, Anna b. Feb 1855 Norway. Marriage abt 1883. etc.
https://familysearch.org/pal:/MM9.3.1/TH-267-12068-96819-72?cc=1477737
Name: Johan Wilson
Age: 64
Estimated Birth Year: 1841
Birthplace: Sweden
Marital Status: Married
Residence: South Dakota, United States
Years in State: 24
Estimated Arrival Year in State: 1881
Years in United States: 45
Estimated Arrival Year in the United States: 1860
Father's Birthplace: Sweden
Mother's Birthplace: Sweden
https://familysearch.org/pal:/MM9.1.1/MMHQ-MT9
Name: Anna Wilson
Age: 51
Estimated Birth Year: 1854
Birthplace: Norway
Marital Status: Married
Residence: South Dakota, United States
Years in State: 22
Estimated Arrival Year in State: 1883
Years in United States: 26
Estimated Arrival Year in the United States: 1879
Father's Birthplace: Norway
Mother's Birthplace: Norway