Hughes describes his as well as the dream by many others like him. We can understand that the poet is talking about the treatment of injustice and inequality for black people by the whites.
This right of independence has becomes a kind of dream now. He has turned old and always yearned for the equal treatment. But he could not find any differences. He feels that this dream can never be fulfilled and he and others like him will never attain this right of equality. He could feel a strong wall/ barrier created by his fellow white people who will not let his dream come true.
Author is an old man now. Now he is thinking about his dream which he imagined about long time ago. He thinks that he has almost forgotten their dream. The dreams become a distant, faded memory that he almost forgets about, until he remembers as he grows older, and the memory of his dreams come back to the front of his mind. He tries and tries to go forth with his dreams. That dreams is still brightening in front of him like a sun.
But now a wall has come between him and his dream. This wall became a barrier to his dreams. The wall seems to grow forever and forever, and it has become so high that it “rose until it touched the sky.” The author means to say that this barrier seems not to be diminishing or to be crossed over in order to reach towards the fulfillment of his dream. With the wall blocking the bright light, Hughes’ dream is in the dark. This means that he is not very hopeful towards the attainment of his dream; he seems that all light of hope is replaced by the darkness. Replaced by a shadow, and says that I am black. The barrier has become like a long dark shadow which have covered his dream and overshadowed it.
Author says that he lie down in the shadow, means he feels surrendered and helpless for this darkness. Next he says that, “No longer the light of my dream before me, above me.” means his dream is no longer above him, the dream is beneath him. He feels defeated.
This can be interpreted as saying that the dream of freedom and equality is unrealistic or he is saying that the dream has been temporarily disabled because of the wall created by others.
The Author says that his “dark hands” that will be able to “break through the wall,” and “find his dream. The author thinks that he wants to break the wall and reach up to his dream.
Now in between the wall and their shadow, only their hand is there, which again denotes the color of the skin. Through this only he can find his dream by breaking the wall. He wants help to break the wall and shatter this darkness into like a brightening a sun in to a thousands of whirling dreams.