Another thought would be what if the senior leader's of the CSA were tried and convicted of treason? It is hard to venerate and put up statues of people who waged war on their country, remember many of the Confederate leaders served in the US military, and/or the US government, then were responsible for the deaths of thousands of their fellow Americans to prop up the institution of slavery. In some ways I think the US lost an opportunity, they won the war, but lost the peace, in an effort to let them down easy.
The British have tried Irish rebels for a very long time time for treason and hanged them.
It did not work for the British, all they did was to create dead martyrs to the cause. Most of Ireland left the union in the end.
In the case of officers like lee he resigned his commission in the US military, before returning to serve his state.
The would convicted of treason not trying to maintain slavery. Even if the CSA fought the war for some other reason the union was not going to let them leave no matter what the cause.
The federal government was very success in ending the war and making sure no states have ever tried to leave the union again.
Start trying people for treason and instead of it being a lost cause it becomes an on going cause that never ends.
I do not see how it affects race relations or civil rights. The union fought the war to preserve the union and race relations or civil right were not an issue that interested them much.
The time to improve race relations in America and the lives on African Americans is the 1960s not the 1860s.
Make all drugs legal in America, as the war on drugs has hit the black community much harder that the rest of America.