Lee freed his own slaves a good 10 years before the war began. Many of them continued to live with him long after the war ended & all slaves had been freed.
People on all sides try to frame that era according to modern times’ society, but it’s comparing apples & oranges. It’s sad & frustrating that people are so incurious, stubborn, self righteous, & willfully ignorant. Few people (it seems) can even fathom a time they haven’t experienced.
They should just stay out of it if they can’t do any better than that. (Sorry if that’s blunt.)
And that is true. All to often people try and judge people from the Civil War by today's standards of racism. In that then there isn't a person from the period who could pass muster.
Lee was only mildly opposed to slavery. So what? Even at that level that set him apart from most of the people in the South who thought slavery was the pillar of Southern society and would be around for generations. Lee's views on slavery or blacks do not make him a bad person or a vile racist. They make him a man of his times, no worse and in many ways better than his peers. He should be judged by those standards.