Just finished Jay Winik's 'April 1865'. Absolutely astounding. Have read MacPherson and Foote, among others, and been all over the battlefields and relevant museums all my life, I figured I knew most all the relevant facts re the Civil War, but this book often had me feeling like a neophyte. I can't express how much additional insight this book brought bear about the motives, decisions and men that made both the war and the peace.
Even if you are not a history type, I'd recommend it. For sheer understanding of this country, there can't be many better books.