About 20 years ago, I got deep into the Civil War after reading Killer Angels. I ended up spending a small fortune on books and magazines. There used to be Civil War bookstore in Dayton Ohio (Morningside Press) that reprinted some of the classics, such as The Passing of the Armies (Chamberlain), Military Memoirs of a Confederate (Alexander), Reminiscences of the Civil War (Gordon) and many others, all of which you can now get for pennies on Kindle.
So, I ended up with over a hundred books and a lot of trivia in my brain. I've recently started re-reading some of them.