The Younger family of five lives in a small apartment on Chicago's South Side, in a year between 1945 and "the present" (1959, when the play was performed). Walter Lee Younger, a chauffeur in his mid-30s, is unhappy with his job and wants to purchase a liquor store with two friends. His wife, Ruth, isn't so sure about the plan. The Youngers have little money—they live with Walter's mother and younger sister Beneatha—and they have a young son, Travis, to support. The whole family eagerly awaits a $10,000 check from a settlement awarded for the work-related death of Big Walter—Mama's husband and Walter and Beneatha's father. Mama, practical and hardworking, will receive and distribute the funds. Walter tries to convince her to finance his investment, but the devoutly religious Mama believes selling liquor is wrong.
Beneatha wants money to attend medical school. While Walter ridicules Beneatha's aspirations, Mama supports her. The family encourages her to pursue wealthy suitor George Murchison, a man Beneatha doesn't love. Another suitor, Nigerian classmate Joseph Asagai, helps Beneatha explore her African heritage.
The day the check comes Ruth discovers she's pregnant with an unplanned child. She considers terminating the pregnancy to Mama's dismay. Walter, upset by the family's lack of belief in his dream, begins drinking heavily.
Without telling her family ahead of time, Mama uses part of the settlement money to make a down payment on a house. Ruth, at first overjoyed by the purchase, becomes concerned when she learns the house is in a white neighborhood. When Mama sees Walter's distress—he's begun to miss work—she gives him the remainder of the money. She tells him to use some for his liquor store investment and put the rest in an account for Beneatha's education. Ruth decides to keep the baby.
While the Youngers are excitedly packing for their move, they are visited by Karl Lindner, a white representative of the "welcoming committee" in their new neighborhood. Lindner is initially polite and claims he wants to start a dialogue. He eventually reveals that the neighborhood residents want to buy back the house at a financial gain to the Youngers to prevent integrating the community. Walter, Ruth, and Beneatha angrily reject the offer and ask him to leave.
On moving day Walter's fellow investor Bobo visits the apartment with bad news. Willy Harris, the man to whom Walter and Bobo gave the investment money, has left town with the funds. A devastated Walter tells the family that he gave Beneatha's school funds to Willy as well as his own share. Mama becomes enraged and begins to beat him.
The family, now in need of cash, considers staying in the apartment. Beneatha talks to Asagai and questions in despair whether progress is possible for the human race. Asagai asks Beneatha to move with him to Africa, where he plans to work to improve the lives of his people.
Defeated, Walter prepares to call Karl Lindner and accept the buyout offer. While Beneatha's ready to disown her brother, Mama asserts that Walter needs their love now more than ever.
When Lindner returns Walter surprises and delights the family by telling Lindner they plan to move into the house after all. As they load the truck Beneatha reveals she wants to go to Africa. Mama tells Ruth that Walter has finally come into his manhood. The play closes with the Youngers vacating their apartment and going to their new house.
