Why are they all from Pennsylvania?

[yanks87]

I think all major cities had candy and baking companies, some focused on non-sport cards, others just focused on the candy. New York had candy brands like Leader Novelty that had all sorts of non-sport cards. Boston had Goudey and World Wide Gum. Chicago was another hot bed, with Wrigley, Cracker Jack and Leaf Brands (Dietz and Overland issues are also from the Leaf family).

At the root of it, immigrants hit the east coast and spread throughout the country. The fact that there are so many brands rooted in PA may be more related to success of start ups setting down roots early, or the fact that the iconic card sets had staying power and coincidentally were all based in the Keystone State.