"A Dream Deferred" is full of powerful sensory images which are undeniably represented in this play, as Hansberry includes the poem in the published work and references it in the title. The question is: "what happens to a dream deferred?" The answer is a series of possibilities: does it dry up, fester, stink, crust over, sag, or explode. It's pretty clear Walter is the one who most exemplifies these images and emotions of an unrealized dream.
Walter wants to do something to have a business of his own. We know he's not particular, because he was interested in a dry cleaning business and now he wants to own a liquor store. He hates his job working for someone else (as a chauffeur) and doing anything else would be better than what he's been doing. He's distraught that he can't provide for his family without help, he's angry that black men don't have as many opportunities, and he obviously feels like he's not doing his job as a man.
"Somebody tell me – tell me, who decides which... women is suppose to wear pearls in this world. I tell you I am a man – and I think my wife should wear some pearls in this world!"
Despite that sentiment, he is not able to do what he wishes he could--and some of that is clearly his own fault. His anger and frustration are building.
When it becomes increasingly clear Walter is not going to get any of the insurance money to invest, he literally explodes. He goes and gets drunk; he walks away from his wife in anger; he is content, for a time, to let his wife get an abortion because a baby feels like just one more burden; he quits going to work; he fights with his sister; he disrespects his mother. He's angry and accusatory and walking around with a giant chip on his shoulder. He feels as if he's misunderstood and certainly underestimated, which is especially hurtful to him:
"WALTER: Man, I’m a volcano, a giant surrounded by ants. Ants can’t understand a thing giants talking about."
The volcano imagery is certainly apt, given the poem's imagery.
Mama finally understands what is happening to her son, and she does give him the money. Of course, he is too trusting and he loses the better part of their inheritance. This is a weight which causes him to "sag like a heavy load." It is short-lived, though, as Mama does what she must to save her family, and especially her son. The play does end with hope, and while the Youngers will never be rich, they will, we think, be content.
It's an interesting twist that the poem lists many images of discontent and rottenness and sickness and shriveling--ending with an explosion. In the play, however, the explosion is not the last thing; is does happen, but it's not the end. Instead, there is a new kind of explosion:
"MAMA: He finally come into his...manhood today, didn’t he? Kind of like a rainbow after the rain....
RUTH (Biting her lip, lest her own pride explode in front of Mama) Yes, Lena."
How Walter sees his life sets the tone for the rest of them. Walter may still hate being a chauffeur; but he has something more than he started with, and there is a hope and anticipation for the entire family as they continue to live their lives. For Walter and his family, the dream may have been deferred, but it does finally become a reality.