Chickamaugua didn't have it (but I was there a few years ago) but Gettysburg did (and I was there last year). Didn't notice it this year at G'Burg when I went, but I bought a bunch o' small booklets by civilians at Gettysburg that I hadn't seen elsewhere.

It can always be found used too. Write the publisher to see if they have any more in stock. Publishers are always happy to sell direct. That's a 30% discount they won't have to give to the bookseller/distributor.