It is located on the campus of the University of Findlay in northeast Ohio. 
The five adjoining rooms display hundreds of original book illustrations for children, drawn from a collection of about 3,400 works. The collection grew from only four original works bought just over 25 years. display in the originals are copies of books for which the work was created, and black binders with more information about each of the designers.
When I visited last week, they let me add the artist's wall, right next to CF. Payne. The museum is free but accepts donations.
Wikipedia on Mazza.
