An antiquarian map store in downtown Chicago
I've located two antiquarian map dealers in the Chicago area, and one is in downtown Chicago very close and convenient to where we will be next month.
Harlan J. Berk, Ltd. is primarily a coin shop (Paige!) but they also deal with maps --- enough so that they will be exhibiting at the upcoming Chicago Map Fair (see http://www.chicagomapfair.com/exhibitors)
Another area map dealer, George Ritzlin, is a train ride away in Evanston, Illinois (where Northwestern University is). Directions and hours are posted at his website linked below.