I have to write an essay talking about the horrors and ugliness of slavery in the movie Roots?

I'm sorry, I haven't seen that movie in a long time. One thing that I do remember clearly is how Belle, (Toby's wife) had been with William Reynolds (the slave owner) for her whole life and had taken care of him. And still, when her daughter Kizzie, broke a rule about learning to read/write, he sold her away. He didn't have any compassion at all for Belle, even though she took care of his family.