No, your head is up your ass. There is nothing to say "thank GAWD grandpa was kidnapped by an African tribe and sold to the Portuguese so now I have the rights of an American citizen." In context it says, that if you aren't a descendant of a slave in the US, more than likely you would have been the descendant of people who to this day have endured famine, who endure to this day deep poverty, who to this day don't have ready access to clean water, who to this day have no protected freedoms, who to this day are subject to tribal wars.
Was slavery evil. Yes, and it is evil to this day as it continues in African nations, in China, worldwide and and even in the US with sex trafficking. But as with many adverse situations, good can come from it, and in fact in the long run did come from it. Ask LeBron. Who would he be playing for in Africa? What about George Washington Carver? What about Booker T. Washington? What about Emmitt Keller ( a great personal friend of mine nobody knows about)? Emmitt's ancestral tribe was wiped out in Africa almost 200 years ago.
To focus only on the institution of slavery ignores the broader realities.
And not all slaves were tortured. Does that forgive abuse, Hell no. But there is no superior right to project an agenda as superior to fact. Many slaves continued to work for their former owners after the Civil War. Many slaves earned modest wages as slaves and purchased their freedom. Not all slaves were abused, not all slaves were uneducated.
As the title says, migration comes in many forms. The Anaszi were one of thousands of tribes over history who migrated due to drought, The Inuit, likewise migrated. Slavery was another way people migrated and history was changed, cultures enriched.