Well, Eric Foner is considered the go to for modern scholarship, so Reconstruction: America's Unfinished Revolution, 1863-1877. There's also W.E.B. Du Bois' 1935 Black Reconstruction in America, which was the first book to argue against the distorted and racist historiography of the time.

Edit: Amazingly, Du Bois was actually nine years old when Reconstruction ended, though he was in Massachusetts so he wouldn't have seen any of the direct effects.