They Met At Gettysburg by General Edward J. Stackpole, who is apparently the one who gave publisher Stackpole Books their name, was originally published by them in 1956 and now free courtesy of them as well.
This is apparently about contrasting the leadership styles of the US Civil war generals.
Currently free @
Amazon (not available to Canadians).
Description (no really, that's all there is, alongside one line of generic praise from Reader's Digest, and I had to go to the paper edition for even that much; you're best off going to the customer reviews if you want to know what on earth this book's subject matter actually covers and not just experience Marketing Failures 101: How Not To Blurb Your Book To A Picky Quasi-Scholarly Audience)
A step-by-step retelling of the battle, with maps, photos, and firsthand accounts.