I enjoyed this single. It's well written and researched, and the author mentioned a few titles that I didn't know about and would like to read.
I think this is an ambitious topic for a Kindle Single, because any attempt to briefly explain the causes for the civil war will inevitably leave a few loose ends. No fault of the author, it's just a lot to cover. Readers who are predisposed to disagree with his thesis will pounce on these dangling threads and pick away at his conclusions. Even objective readers may find themselves wondering about bits that don't seem to fit. For example, why were so many rebels willing to fight and die to preserve slavery, even though a great number owned neither plantations nor slaves? And why were so many Unionists willing to give their all to preserve union with a region that embraced slavery?
Historians have given us thoughtful, compelling answers to these kinds of questions, but it generally takes them a lot more than 26 pages to do it. Kindle Singles are described as, "Compelling ideas at their natural length." I'd agree that this topic is compelling, especially as we arrive at the 150-year anniversary of the start of military action in the civil war, but its "natural length" seems much longer.
So if you're trying to decide whether this single is for you, I'd suggest you might consider it an appetizer. If you've read a lot about the civil war, you'll enjoy this well-written synopsis of the run-up to the conflict and its aftermath. If this period of history is new to you, then you'll probably be amazed by this account and may want to follow it with other books about this turning point in US history.