Speaking of books on U.S. Commemorative Coinage, here's an interesting item about early 20th century books on the topic.

Bruce H. Smith writes:

I don't know how Harry Rapp comes into the picture, but the American Numismatic Society published Howland Wood's book The Commemorative Coinage of the United States in 1922. I don't have a copy for comparison. The ANS published an update by David M. Bullowa titled The Commemorative Coinage of the United States 1892-1938 in 1938 (Numismatic Notes and Monographs No. 83). I have that one on my shelf, and in it Bullowa devotes the volume to Wood, who passed away that year. He writes that Wood's 1922 work was the "point of departure" for his study.

Interestingly, as shown in the image above, the title page reads as follows:

Bruce adds:

Perhaps Rapp was working on a manuscript unawares that Bullowa was doing the same. Can anyone tell us more about Rapp and his book?