The reference to 2500 Lincoln (Illinois) halves 'sold at face value' dovetails directly into my interest in circulated commemoratives. Do you have any insight into the source data to support Mr. Green's conclusion?
I was hoping that someone would pick up on this and ask a question!
To my knowledge, there are two known/verified sources of 1918 Illinois Statehood Centennial half dollars that saw circulation:
1) Q. David Bowers reports that a bank in Iowa City, Iowa received a $1,000 bag of Illinois half dollars (2,000 coins) in 1919 as fulfillment of an order it placed for regular-issue half dollars. As coins of the denomination were needed locally, the bank tried to distribute them alongside regular-issue half dollar coins. It appears, however, that the task proved more difficult than expected as local residents were hesitant to accept the coins due to their lack of familiarity with them/their design. (The Walking Liberty design was also relatively new at the time.) Eventually, the bulk of the coins did get distributed.
2) It is known that a bank in Springfield, IL discovered ~30,000 Illinois Statehood Centennial half dollars in its vault when an inventory audit was conducted in 1933 during the Franklin D. Roosevelt declared "Bank Holiday;" it is believed that the coins had initially been purchased (and held) for the local Chamber of Commerce in 1918. It's also known that the majority of the discovered coins were sold to coin dealers at a small advance over face value, but that a portion of the coins were released into circulation.
Was the number released truly 2,500? The Green book is the only reference I've seen in which a specific number for the coins released into circulation has been published. Did he have inside
information due to his Illinois residency? Did the bank in question officially report the figure locally and Green became aware of it? Did he publish his best estimate based on anecdotal information?
I don't know, but I continue to look for an answer!
To your other request/comment...I've started a post about classic-era US commemorative coins that were placed into circulation, but it's still in early draft form. I'm not sure when I'll get back to it to complete it, but I'll try to bump it up on the list!
I briefly referenced the Springfield Bank situation in a previous post: 1918 Illinois Statehood Centennial - Trivia
I'll update things when/if I find more.