It used to be, a library committed to local information had to keep it in a “clippings file” or “vertical file.” The local history room at the Duluth Public Library still has one and has a master entry on clippings about authors from/in Duluth.
As usual, this is a treasure trove, but I don’t know who all these people are. If you know one I need to know, let me know in the comments below.