You already know why but I'll explain it anyway
You need these things to achieve social cohesion in any language. Usually people mean common people as in common ethnicity, but this is Murrica so it's just gonna have to be in a civic sense. But because of that, having a common language and common memory is impossible.
Robert E. Lee was a distinguished man who had a distinguished father who served under George Washingtonand whose uncle signed the Declaration of Independence. He was honored for his service during the Mexican-American War (You know, the one where the Mexican Republic chimped out in retaliation for the Texan War of Independence and then subsequently lost all of their territory in what we call the US now.)
The first thing he did when he inherited 196 slaves from his father was free them all. He spoke of his disdain for slavery in his letters, despite the common narrative that he was the Hitler of the South who did many many bad things. He sided with Virginia because he was loyal to his home state in the face of growing Federal power, and the last thing he wanted, like Lincoln, was for the Union to be forever torn by the schism of the war, to the point that a peaceful reconciliation was impossible. Writing his resignation letter to the US Army was so heartbreaking for him that he held onto the damn thing for a full day before sending it out because he kept pacing around his room and weeping. Contrary to how history remembers his army, Robert E. Lee was strict in preventing his forces from employing Total War tactics. No raping, pillaging, and senseless murder as long he was around. (Unlike the Union armies that are hailed to this day as warriors of emancipation despite pillaging property and raping slaves). On the same day the Emancipation Proclamation came into effect, Lee freed even more slaves from servitude, despite having been jumped by slaves several times before, who all thought he'd probably have them killed or some shit.
Lee's vision of a Union choked by Federal rule at the death of the rights of the state to hold themselves against that rule came true.
Lee wasn't a bad person. Many of the Confederates weren't bad people, and hell, many of the Union troops weren't bad either. Everyone chooses to recognize the war as a clear divide between Good and Evil based on the issue of slavery, while ignoring the other issues that divided people across the country, as if the very dichotomy of a Confederacy vs a Union doesn't automatically imply that the people who called themselves the Confederacy may have also had a problem with government overreach and not just slavery
We're here because no one who fought on the wrong side of history will ever be remembered as human, part of our history, or even fellow Americans. They'll forever be remembered as traitors who don't even deserve to be a part of the social memory of the country. Even Ivan the Terrible has at least one fucking statue in Russia.
Fuck this earth.