Interesting. By "opposed slavery" do you mean to say him saying "The blacks are immeasurably better off here than in Africa, morally, socially & physically. The painful discipline they are undergoing, is necessary for their instruction as a race, & I hope will prepare & lead them to better things. How long their subjugation may be necessary is known & ordered by a wise Merciful Providence. "
I mean he called slavery necessary. He OWNED slaves, and actually was taken to court and lost by holding free blacks as slaves. But hey, he opposed it.
Just like he opposed secession by joining the states seceding and taking up arms against the USA. Ted Bundy can talk all he wants about how he opposed murder. But his actions are what we judge him on.
And "impeachable integrity" Is that when Lee had to punish his slaves for the crime of escaping he was “not satisfied with simply lacerating our naked flesh, Gen. Lee then ordered the overseer to thoroughly wash our backs with brine, which was done.”
Maybe it was his response to the soldiers in the Battle of Mt Crater who slaughtered black Union troops trying to surrender by doing nothing at all to them.
Maybe it was his allowing his Army to abduct any free blacks they came across and enslave them?
Maybe he showed that "impeachable integrity" when Grant offered a POW exchange and asked for black soldiers to be returned as well and Lee responded “negroes belonging to our citizens are not considered subjects of exchange and were not included in my proposition.”
Or maybe it was that "impeachable integrity" that caused Lee to stop the Washington and Custis tradition of respecting slave families, by hiring them off to other plantations, and that by 1860 he had broken up every family but one on the estate, some of whom had been together since Mount Vernon days.
This is why we should read history from the mouths of those who lived it instead of wanting to re-write it based on memes and statues.