A reasonable acid test as to whether you, regardless of your race, would have freed your slaves in the antebellum South is to ask whether you’re vegan for moral reasons now, or, if you’re not vegan, whether you would consider going vegan for life.
If you’re not an ethical vegan and wouldn’t even consider it, you almost certainly would not have freed your slaves in the antebellum South. It is very easy for most people to go vegan today. It was significantly more difficult (much more of a sacrifice, anyway) for most slave owners to free their slaves prior to 1865.
If you are an ethical vegan or would seriously consider it today (especially after learning why and how!), then you *might* have freed your slaves prior to 1865.
I look forward to the day when we’re as disgusted by speciesism as any other prejudice.