Great book on Civil War

I just finished reading John Keegan's "The American Civil War: A Military History."
I've read a number of Keegan's books, including his wonderful book on WW II, and I find they always enhance my understanding of things I thought I already knew.
The Civil War book had several revelations. First: Lincoln, as commander in chief, understood the war better than any of the West-Point-educated generals. Richmond hardly mattered. Lincoln knew that it was a war to defeat an army.
Second: Grant really was a great general. Yes, he butchered nearly 100,000 of his own soldiers. But he knew what he was doing. Keegan's brilliance is that he shows how the territory -- the geography -- where the armies fought dictated the kind of war they fought. Keegan also shows how the deep-seated beliefs of the two sides (and the fact that they fought in units comprised of their neighbors and friends), created a level of bravery and a frequency of battles that has never been seen in any other campaign. Only a willingness to fight (and an economic and demographic advantage) like Grant's could have prevailed. Keegan reminds us that he had to conquer hostile territory against an entrenched enemy.
Third: Sherman's March to the Sea was a much more daring military campaign than I had realized. After reading Keegan's book, I am amazed that even late in the war, the Southerners couldn't cut Sherman's tenuous supply lines that stretched 900 miles to Louisville.
Every time I read one of Keegan's books, I am reminded that winning wars really matters. Sometimes, when reading history, it's tempting to think that historical developments are inevitable. Reading a military history is a reminder that things could go wrong and that history could have developed in very different ways.
One criticism of the book: despite acute attention, I couldn't understand Keegan's explanation of how Grant conquered Vicksburg. As Grant and Lincoln expected, that was a crucial event, opening Tennessee and eventually Georgia to Union conquest. But Keegan's explanation of some very sophisticated tactics lost me. One of my reactions to this book is that I need to read a book about the battle of Vicksburg.
If you care about America, this is an excellent choice for your mental library.