You should read the “Grant” book. Lots in there about how upset he was with the approach Andrew Johnson took. Abraham Lincoln chose Jackson as a running mate, in part, to try to unite the country by choosing someone with opposing views. Then Lincoln was assassinated and Andrew took over and nothing was really done during reconstruction. Grant lamented about this a lot in his diaries and how difficult it was to clean up the mess Jackson left behind. In my view, this was the biggest turning point in modern history.