look this isnt worth turning this into a huge flame war or north vs south or w.e. but your basis of facts is on a movie? not a documentary, but a movie. I guarantee it would have been at least 100 years before slaves were free there's no proof and no logic behind all the plantation owners who hated non Anglo-Saxon white protestants to say, oh we won, so now all you slaves can go and we can be friends now. again, they were mad at the north for telling them they couldn't have slaves, so why would they free them? but its irrelevant because it was impossible for the South to win the war because the Union had 2 times as many people, 97% of the fire arms, all the manufacturing plants, and most of the rail road systems.
Now heres how I see the mosque in NYC as being different from the confederate flag. At one time, Basically everyone in the south was either for slavery, or noncommittal, because opponents of slavery would be driven out of the south. So, at the time of the war, and when the confederate flag was conceived, the supporters of the Confederacy overwhelmingly supported slavery. And therefore the confederate flag was, of course extremely offensive to, obviously, slaves that were oppressed at the time, and also the free blacks in the North because it said, hey, if we had it our way you would be back on a plantation. Oh by the way, this is going off on a tangent, but during the war, the Union allowed black soldiers, and if they were captured in battle, the confederate soldiers would torture them to death, and if they captured a white soldier, they would kill them right away. Anyways at no point were all muslims extreemist or anywhere near that, however, at the time most people that were part of the confederacy and waved around there confederate flags were for slavery and therefore extremely racist. So black people have a logic reason and right to be offended by the Confederate flag.
Yes, the south was playing an Offensive defense at the start of the war but saying "we only did away with our polite and civil ways after we were invaded" doesn't make sense because you weren't invaded. also i didn't know polite and civil including enslaving a group of people because they had a different skin color.