That Grant was a mindless butcher is part of the pernicious Lost Cause myth spread by the South after the war, paired with depictions of Southern leaders like Lee as noble gentlemen heroes. In recent years there's been a lot of work done to help overturn the myth of Grant as an incompetent corrupt drunk; an excellent recent book on this is the biography Grant by Ron Chernow.
This is great. It’s pretty fair and balanced.
https://www.amazon.com/Grant-Ron-Chernow/dp/159420487X/ref=mp_s_a_1_1?ie=UTF8&qid=1539334724&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=grant&dpPl=1&dpID=51QjQQuYcmL&ref=plSrch
Sorry for the formatting, I’m on mobile.
That Grant was a mindless butcher is part of the pernicious Lost Cause myth spread by the South after the war, paired with depictions of Southern leaders like Lee as noble gentlemen heroes. In recent years there's been a lot of work done to help overturn the myth of Grant as an incompetent corrupt drunk; an excellent recent book on this is the biography Grant by Ron Chernow.
The currently popular Grant biography is good.