Kris:

I have no idea about the inate value of the book itself, University of Michigan publishes a reprint in their historical book series. The book clearly has a context value in who it belonged to and what happened during the war. If it was mine, I'd likely let my son have it with a good discussion about what that particular book means, i.e. why and how it became PE Burke's and what it may have meant to him as he was a young man of 32 under taking the honor and distinction of ordering men into battle. It may be worth having a conversation with a knowledgable book expert about what to do to help protect it, covers, protect the binding etc. If there was little to no interest, then an appropriate donation to the rare and historical book collection of the local university might work. I'm sure the library folks at Wilson's Creek Battlefield could give you a few tips as well.

John R.