Hunting Passenger List

I am looking for the name of the ship and information about my grandparents' immigration to America. They were from Christiansund, Norway, and came to Chicago, IL, in either 1888 or 1889. Possibly their arrival date was May 26, 1889. My grandfather was Albert R. Olsen, b. 12/18/1866 or 1867. My grandmother was Bertina Larsen Olsen, b. 2/18/1870. Mary McWilliams