Map of Censorship in Iowa Libraries during 1918

I know I've mentioned this before, but there is a wonderful Google map that shows all the book bans and challenges in the U.S. over the last 3 years.  When I ran across this map a while back, it gave me the idea to do a similar thing with the Herbert Metcalf letters that inspired my WWI Iowa libraries project. (Metcalf was the man to whom librarians around the state sent letters indicating that they had removed items from their shelves in response to his request).
I made the map and used it for a class presentation, and just recently dug it back up while I was poking around Google. For those who are interested in Iowa or World War I history, this might be of interest to you. You can find my map at this link.
There are a couple things I should point out about this map:
A cursory examination suggests that censorship activities were clustered in the Eastern half of the state. While I have no evidence to the contrary, this is not an assumption I can get behind 100 percent. Part of the reason is that we may not have all the letters written to Metcalf: some might have been destroyed or misplaced, as often happens with office paperwork.
Also, I do know for a fact that the Metcalf letters do not represent all the censorship activity taking place in Iowa that year: For example, Cedar Rapids' library removed books, but there is no letter in the Metcalf paperwork from anyone on their staff. On the contrary, there is a letter from Burlington Public Library, but no record of their removing materials anywhere in the library's records. So, while it does seem that a lot of this censorship took place in Eastern Iowa, we will never know for sure unless someone goes through the records of every Iowa public library.
Another thing to point out for those using this as a tool to study World War I-era history is that it is only for one year: and to be precise, only for the first few months of that year (1918). 1918 was the year when it seems censorship efforts really kicked into high gear (although censorship was taking place earlier than this--see Wayne Wiegand's book, An Active Instrument for Propaganda, for a national look). I point this out to avoid misleading people into thinking it covers the entire wartime period. It occurs to me that it might be helpful to go back into the map and add dates to each entry that match the dates on the letters, and hopefully I will have time to do that soon.
Lastly, these letters raise (and in some cases answer) questions about what libraries did with these books after they removed them. Most simply indicate that books were 'removed from shelves' or 'removed from circulation,' but if you look at Forest City and Villisca, you'll notice that their librarians both burnt the items they felt were 'pro-German.' Most libraries, however, do not indicate what they did with books once they were removed. The meeting minutes from Davenport Public Library indicate that theirs were held by the library board, so it is possible other libraries retained their books in storage. Also, look at Des Moines Public Library--the librarian removed a lot of items! For those who are curious, that is the same Forrest Spaulding who later drafted the Library Bill of Rights. I should point out that I don't think these libraries were intentionally throwing their patrons under the bus to get behind the war effort: I suspect they removed books because the staff and library boards felt it was in the best interest of the patrons. While I would love to know, I have yet to find out any information about whether the removed books were restored to the shelves after the war.