I'd just suggest reading the book and highlighting any relevant points... I did this essay when I was in school and it was really easy. There are a lot of points in the book which you can talk about..
I read it last year and I think there was some sort of racist aspects to the way the other thought of him. He was treated like an animal as he stayed in the stable. Another point is that the others said not to talk about him because he's coloured or something.