“If you were a 20 year old, why would you think you had no prospects of ever owning a slave? Why wouldn’t they think they could become prosperous and own slaves some day?”
That’s a fair question. I would reply that, given the conditions that then existed, it would be unreasonable for a poor 20-year-old to think that he would become that prosperous.
Our history of the period was full of examples of men who started out poor and became that prosperous. Andrew Jackson. Thomas Jackson. Abraham Lincoln.
I don't see any evidence in history that would be the case. America, North and South, was the land of opportunity for people with dreams and ambition. There was no welfare mentality and no such thing as a permanent underclass as we have today.
Many many people began with nothing and ended up very wealthy and successful back then. Think of people like Ben Franklin, John Adams, Alexander Hamilton, Andy Jackson and even Abraham Lincoln.