The south was simply stuck with and happy with the system of slavery. There was no longer a need to import them. They were reproducing faster than they were dying off.
Slavery existed all over the northern states also, especially New York. The biggest slave owner in the state of SC was a black man. And when the murdering Lincoln “freed” the slaves with his bogus emancipation, he “freed” slaves in a country he had no jurisdiction, as in the Confederate States of America. He left alone the slaves that were in border states like Kentucky and Maryland.Precisely because the majority of those states sided with him. And getting back to Jefferson, most REAL historians think his brother was the one that fathered the children with Hemmings. AND, if he had an “affair” with Hemmings, his wife was dead and he was an old man. Nothing to see here for Jefferson haters, so move along.
Jefferson seems to have been conflicted--some of the strongest criticisms of slavery in that era are found in his writings, but he continued to hold slaves himself. He had a comfortable life at Monticello and could console himself with the notion that he treated his slaves well. Since he was deeply in debt I don't know if he could have legally given it all up and set all of his slaves free. If he could have it might have meant living the life of a poor dirt farmer--which is what the majority of his fellow-citizens were but that's not an easy change to make if you are used to a life of relative luxury. How many dirt farmers in Albemarle County drank imported wine?
It's easy to criticize him from this distance but we can't say how we would have acted if put in his situation.