My great grandparents, Patrick (abt 1820 - 1880) and Margaret Sweeney Callahan (abt 1830 - 1906), came to Juneau County about 1855 from Massachusetts, then moved on to Waseca County Minnesota about 1865. With the same surname, same county in Wisconsin and similar timing your John might be related to my Patrick.
I have found nothing about origins in Ireland or date(s) of migration. There was a daughter Johanna born in New York state about 1849, but she might have been from a previous marriage for Margaret, if an 1852 Massachusetts marriage record is theirs. They went on to have six sons.