Crook lives in a barn seperate from the others. This physical seperation signifies the effect of racial discrimination in America - Crook is marginalised in society as a result of his race. His crooked back further signifes how he has been oppressed. He is being pushed closer to the ground, fighting to stand upright in the face of adversity.
Furthermore, the other characters consistently refer to Crook as a "nigger" which shows how racism is taken for granted. This further highlights how Crook is dehumainsed as a result of his race as he is denied even a name. He is further denied possessions, symbolising his disadvantage and lack of privilegdges.