The web site http://www.irishgenealogical.org/igsi_published/orphanages/o...
has a brief history of Catholic orphanages in Minnesota.
The web site refers to two books written by Sister Claire Lynch on the history of orphanages in Minnesota. According to this, the information contained in the two books is fairly comprehensive as to the dates orphanages operated, the names they operated under and so on, and should enable anyone to look up inmates of these institutions in the appropriate census records. Copies of the books are held by the Minnesota Historical Society (http://www.mnhs.org
) and the Minnesota Genealogical Society.