Isn't it pretty clear and straight-forward? It was based on the beliefs (regardless of the degree to which you might think from your perspective that those beliefs accurately represent reality or not) that many people held back then that there are significant racial differences between slaves and people, and the same rules do not apply to white ones as to black ones because they are not the same species, they do not have the same brains/possibilities/rights/etc. Just like they did not grant any freedom to animals or trees.
However much one might disagree with the basic premise of the racist argument, it does not make it a hypocricy freedom-wise. If someone was holding these racist beliefs in this past USA (and many of them did) - they could very well believe in freedom of all people, and at the same time not consider the slaves "people" based on their racist beliefs that there are actual important and significat differences between those races.
Just because someone treats someone else badly doesn't automatically make it a hypocricy, the world is just more complicated than that and there are plenty of examples of violence or exploitation being based on well established logical thought systems or even ethical (from the point of view of the exploiter) beliefs. And this is important because if you want to make a change in a society, you might benefit from understanding how that society actually thinks and what ideology is behind it. Just calling it a hypocricy is not good enough.
Hypocrisy of deed is not covered up by some fig leaf of convenient belief systems.
Wikipedia says he fathered 6 children with her. Do you honestly believe that he thought dark complexion was some seriously different subhuman race?
Personally, I find it hard to believe that Southern whites, who lived in such close proximity to their slaves, actually believed this. It sounds like convenient bullshit that you would try to tell yourself in order to justify what you are doing. You see these people everyday, you speak to them, you own generations of them, and they raise generations of your own children in your house (mammies). Of course you would see enough to know that they are the same species and every bit as human as you are.
At the end of the day all of these high minded ideals are just excuses to justify ones own actions and world views.
Does CNN have a right to choose who can use their broadcast platform?
Is freedom of association allowed?
CNN will not invite you to rant unless you serve a demographic purpose for reaching its audience.
If you associate with the wrong political groups you will be spied on, and your organization will be disrupted intentionally by informants. Yes, in America.
So, as long as you are within the bounds of what the conversation is defined to be you enjoy freedoms, but then what has freedom become if so?
When I said that these distinctions are the determining factors of empires I am saying that these systems function quite similarly, but the distinctions in how they justify themselves are the breathing room where they are successful or fail to convince the population to go along.
The history of liberalism, from J.S. Mill to Jefferson is fraught with hypocrisies and inconsistencies like this[0].
[0] https://en.wikipedia.org/wiki/Liberalism:_A_Counter-History
But we do the same today. A lot of us have pretty unsustainable lifestyles as far as the environment goes but we make ourselves feel good (or even superior to others) by adding a little bit of organic food and organic clothing. The hypocrisy gets even more exaggerated when stars promote climate change awareness while flying private jets all over the world and living in 20000 square foot houses.
The interesting thing is that a lot of famous hypocrites still do good. Maybe not with their own lifestyle but by other people being motivated to do better