I do believe that there are African Americans who have thick accents. My mom has a thick accent; my relatives have thick accents. But sometimes you have to adjust when you go into the world of film, TV, theatre, in order to make it accessible to people.
“In this country protection has always, to some extent, existed; but at some times it has been efficient, and at others not; and our tendency toward freedom or slavery has always been in the direct ratio of its efficiency or inefficiency.”