[jonathankoren]

It was an explicit reconstruction policy. The government wouldn't prosecute the traitors for treason, because we were once again a big happy family. This is why 10 Army bases are named after confederate generals[0]. Sometimes, even after really crappy generals. (See Fort Bragg [ibid.])

The modern movement of embrassing "southern heritage" with the confederate flag, holidays, and monuments come from an reaction to the civil rights movement. Stone Mountain in your example was the site of the founding of the second Klu Klux Klan, which was then purchased by the state in 1958. The site and the history of memorial are deeply entwined with the KKK. I truly urge everyone to read the Wikipedia page about this site if you have any doubts about this.[1]

[0] http://time.com/3932914/army-bases-confederate/ [1] https://en.m.wikipedia.org/wiki/Stone_Mountain