I recently read James McPherson's new book This Mighty Scourge: Perspectives on the Civil War and would recommend it to all. Each chapter of the book is an essay, some of which have already appeared in various journals, on a single topic. The overall theme is simply the Civil War, not battles or politics, although there are chapters on those topics.
The reviews I've seen of it online have run the gamut from people who proclaimed it a masterpiece (most likely an exageration) to people who were disappointed that it was too general in scope. I would agree with those reviewers who thought it too general, but that is part of the reason I liked the book.
Some of his chapters cover topics I would never take the time to read a full book on. These are topics like the Underground Railroad, Jesse James and the Brahmins. The essays on particular battles are not about the ebb and flow of the battle but how it fit into the war, how it changed the war, and what other factors were going on that influenced the campaign.
Another complaint of some reviewers is that McPherson himself broke no new ground, that he was mainly synthesising the most recent research. This I also liked. During my last year of my history degree I had to read a ton of historiographies (basically the history of the history) and these were mainly tedius and boring. In This Mighty Scourge though McPherson provides a ton of historiography and makes it enjoyable reading. When historiography is done well it is very interesting and informative. It also helps mold questions for further research by making the opinions of the last several historians succinctly known and differences exposed.
Yes this book was a general overview and yes it broke little new ground. That is what made it enjoyable. Very infrequently is a book of this style done well but McPherson did it here. Often this sort of book comes across as so general as to be childish, or the historiography is so boring that it would sell better if the title was changed to "Nyquil: The Very Drowsy Formula."