One of the organizations that sponsored that show is The Center for Photography at Madison: http://www.cpmad.org/ A very nice group of people.

The show you saw is held every two years I think, though it might be every 4 years. I have the brochure at home and can look to be sure, but it isn't being held this year I know.

There is a group in Milwaukee too: http://pictorialists.com/ They have a lin to Wisconsin area camera clubs.

Best,

Will