Who is mr.morrison and why had he come home with cassies dad?

Mr. Morrison is an extremely big and strong older man whom Papa brings home from the railroad. Mr. Morrison got in a fight with some white men and was fired from the railroad. He helps to protect the Logans, watching outside their house at night, and stays on with the family even after he injured the Wallaces when they attacked Papa. His own family was brutally murdered by a lynch mob during Reconstruction and he says that the Logans are like family to him.