How is Mr. Morrison a protector for the Logans?

From Big Ma's stories about her husband and sons to Mr. Morrison's willingness to risk his life to protect the Logans, it is clear that love of and devotion to family is the motivation that drives the majority of the characters in this novel to act as they do. Mr. Morrison is physically intimidating and people, even white people, think before messing with the Logans He is described as a "human tree ... towering high above Papa's six feet two inches. The long trunk of his massive body bulged with muscles, and his skin, of the deepest ebony, was partially scarred upon his face and neck, as if by fire."