I did several different searches on a wide variety of topics just to get a feel for the site. By using the advanced settings you can really narrow your searches. The basic search is nice if you have a topic but not sure where you specifically want to go. I am always amused when searching sites, any site, not just this one, and you can do search for dog breeds and get books on psychology. Makes me want to read that book to see how it relates to dogs :) Anyway...
I found these 3 books about the constitution. I don't remember celebrating Constitution Day as a youngster, but possible it is so far in the past I forgot.
Our Elusive Constitution : Silences, Paradoxes, Priorities
Hoffman, Daniel N.
State University of New York Press, 1997
Representing Popular Sovereignty : The Constitution in American Political Culture
Levin, Daniel Lessard
State University of New York Press, 1999
The American Republic : Constitution, Tendencies, and Destiny
Brownson, Orestes Augustus
Project Gutenberg
With the Western History search I added South Dakota as it would make sense since this is where I live. I didn't find any books published in SD but did find some books about SD. I could have been searching wrong and there were some published in SD and I just missed them.