https://www.youtube.com/watch?v=vactqAELEbc This Chris Hayes podcast is interesting in this regard.
Absolutely not, high slave proportion ares had the highest proportion of lynchings, and the worst socio-economic outcomes for black people than low-slave areas. White Obama vote share in 2012 was much lower high-slave counties than low-slave counties. The whites that lived in these counties are also the ones that voted for the republican candidates the most, and for the furthest right candidates (David Duke), and were for sure the areas with the lowest white proportions in AL voting for interracial marriage.