What are the 2 history textbooks for Army OCS?

I'm just starting out going the traditional path. So far I just know that it's beneficial to learn the start and end dates of all major American campaigns and dates of key battles as well. I'll try to reveal more as I know it.

It's the ol buzzard giving the exam - and the way the damn questions are written. For example - its not knowing when/where a particular conflict took place - its what avenue of approach was taken - or was battle drill one fucking alpha employed? (I kid, but you see the point).

Honestly it’s not the content of the test, it’s the way that the answers have to be written. I honestly don’t remember the format from my time at OCS and I’m not sure if it’s changed, but knowing Dr. Campbell it probably hasn’t. Studying beforehand also won’t really do you any good because it’s based off the info that he provides and not necessarily what’s in the book, again that’s how I remember it. Honestly I wouldn’t worry too much about it.