Lena Younger is the matriarch of the Younger family who live in a cramped Chicago apartment far too small for them. Lena shares the apartment with her son, Walter, his wife Ruth and their son Travis, as well as Lena's college-age daughter Beneatha. Walter is an angry young man whose ambition far outpaces his ambition and his goals for his life. He works as a chauffeur and Ruth adds to their income with a part-time maid position. Although Lena has now retired she is awaiting a check for $10,000 as she is the beneficiary of her deceased husband's life insurance. Walter thinks that the money should be given to him to invest in a partnership in a liquor store. Ruth doesn't really approve of his plan and doesn't want her husband involved in a liquor store. She firmly believes that the money is Lena's and hers to use as she desires. Lena does not approve of the liquor store either. Impatience with his family and what he sees as their lack of support coupled with his impatience waiting for the check to arrive makes an angry young man even more angry and bitter. He takes his disenfranchised feelings out on his family. He is hard on his son and he mocks his sister for her lofty goal of becoming a doctor.
Travis has started to earn extra money carrying out groceries at the local supermarket. Ruth reveals that she is pregnant and this worries Lena because the couple can't even afford to support the child they have; another baby is financially out of their reach.
When the check arrives, Walter begs his mother to lend him the money to fund his portion of the liquor store. He has even gone to the trouble of having a friend write a business plan to show her but she refuses to read it. Part of the check is spent on a house in the predominantly white area of Clybourne Park. There will be much more space and Travis can have his own bedroom. Lena will be able to garden. The money left over will be put towards Beneatha's education. This infuriates an already-angry Walter and the chip on his shoulder grows larger. He goes on a three day drinking binge and loses his job. Lena finds him crying over his lost opportunities and unattainable dreams and she relents, giving him the rest of the money. He and his friends give the liquor store money to another acquaintance, Willie, who is going to use some of it to bribe city officials into fast-tracking their liquor license. There is a problem with this plan though; Willie absconds with the money.
This plays out against a background of trouble brewing at Clybourne Park. An official from the Home Owners' Association visits the Youngers and tries to encourage them to reconsider moving to the neighborhood. The white citizens of Clybourne Park do not want a black family moving into the neighborhood. The representative offers Lena more money than Willie stole from Walter if she will relocate elsewhere. Lena stands firm. Despite everything that has happened, she refuses to cancel the sale and moves her family into Clybourne Park, determined to give them a better future.
