Texas has had the same flag since it seceded from Mexico and became independent. Republic, U.S., CSA, U.S. again, why is there not vitriol about the Texas flag?
One of the primary issues of abolishing slavery was that it was a national problem that needed a national solution, and no solution was ever put forth by the abolitionist or Lincoln or the Republican party (other than Lincoln's idea to emigrate or deport them). Slave labor was labor, pure and simple (though wrong of course). It's not as if slave owners did not have to expend their capital on their slaves for housing, food, supplies, equipment, furnishings, clothes, etc., etc. I don't think it would not have mattered to many if they simply had to pay a wage to their laborers instead of spending the same $$ to support them. That may have even been more economical once they started charging rent on the shacks they lived in on the owners land.
The abolitionist movement was still an extreme minority in the North, and the North benefitted from the institution of slavery in the south, not just on a macro level but that most of the slave merchants were from the North. Right or wrong, and we certainly agree and know it to be wrong, but the practice was legally and constitutionally protected, and slaves were "property". If the national government is going to move to liquidate private property, there has to be equitable compensation. That was never discussed or proposed.
The failing of the 13th Amendment was not the amendment itself, it was the lack of "what then", no relocation programs, no education programs, no assistance, nothing. And those newly freed blacks, most of them could not move North due to the rampant black codes of the North. So, you "free" them, but nothing in their life changed. When they were able to move north more freely they experienced much of the same discrimination and segregation, unfortunately.
What is giving rise to neo-confederates, who are completely separate from those that are proud of Southern heritage and may be proud of a Confederate soldier ancestor who did not fight for slavery but for the concept of a limited federal government, is the demonization of ancestors. As if it was only ever a handful of southern white crackers that ever had anything to do with slavery, disregarding the fact that all original colonies had slavery, most slave-merchants were from the north, there were free blacks who owned slaves, the Dutch, etc. didn't have to capture slaves in Africa as much as buy or trade for them, many northern states that did not have slavery also would not allow blacks to live in their stare, etc., etc., etc. Two wrongs do not make a right, but why should only one segment be demonized and the other get a pass???
I am not a CSA apologist who says the war had nothing to do with slavery, that is ridiculous. But the vast majority of soldiers on either side did not care about slavery and felt the exact same way about slaves/blacks. Largely the war was fought by one side wanting to preserve the Union with a strong federal government while the other side wanted a limited federal government with the states having co-equal power the way the Constitution was actually written...