I have to admit I am a bit of an amateur enthusiast where African American history is concerned. These are just the conclusions I have reached based on what I have read about the subject. I think I’d particularly recommend anything by Kenneth M. Stampp, C. Vann Woodward, and Eugene Genovese - all fairly old now, but absolute classics.
I would add, when I talk to British people about the trans-Atlantic slave trade, they often emphasize the idea that racism was invented around the time that the slave trade took off in a big way as a way of justifying treating black people as chattels (and as labor in British colonies thousands of miles away). However, from the American point of view, perhaps because slavery actually took place right here on American soil, I think there is a lot of evidence that white people in the South genuinely believed that black people were inferior and that it was in the interests of both races for black people to be kept as slaves. During the Jim Crow era, it was also repeatedly argued that segregation was actually in the best interests of black people as well as white people and that the separation of the races was natural.