Wikipedia says
>According to the latest available data at the World Prison Brief on May 7, 2023, the United States has the sixth highest incarceration rate in the world, at 531 people per 100,000
531 people per 100,000 works out to about half a percent. Meanwhile during slavery in the US, wikipedia says
>The slaves of the colonial era were unevenly distributed: 14,867 lived in New England, where they were three percent of the population; 34,679 lived in the mid-Atlantic colonies, where they were six percent of the population; and 347,378 in the five Southern Colonies, where they were 31 percent of the population.
Even in low slavery areas, the slavery rate is higher than current incarceration rates by several fold.