2nd great-grandparents on the ship Concordia 1871

I'm new to the message boards here at the site but have managed to find my 2nd great-grandparents on the ship Concordia that left Norway 15 April 1871 and landed in Quebec 22 May 1871. I have a couple of questions I'm hoping some can answer or advise me where to look for further information. I'm looking to find when and where they left Quebec for the US because they ended up in Chicago, Illinois, which is where my mother's side lived their entire lives. Also my 2nd great-grandfather seems to have either died or disappeared after 1878, his wife is listed in the 1880 US census as a widow living with her four sons and her brother Martin Johnson in Chicago. I know my great-grandfather was born (allegedly) in Chicago but recall my uncle mentioning Canada and I'm wondering if perhaps he was born there and THEN they came to the US. Any help or advice would be greatly appreciated.