The major theme in “A Raisin in the Sun” concerns generation in two senses--personal growth despite harsh social and economic opposition and family lineage. The title comes from Langston Hughes's poem, which compares a dream deferred too long to a raisin rotting in the sun. The Youngers are tired from the struggle to survive, but a promise of growth is inherent in the family name and in recurring plant and birth images. Mama's prize possession is a scraggly, little plant that gets fitful sunlight from the only window in the apartment. Just as she regularly tends its growth, so also tries to nurture her family and raise them to be mature adults. Lena is happy about the new house because it has an area for a garden, and her family gives her gardening tools and a sun hat betokening her role as the family nurturer (Kappel 103). The plant is the last thing she takes with her when they move.

Birth imagery is also essential to the generation theme. Lena and Walter Sr. lost a baby earlier, and, now that Ruth has decided to abort her pregnancy, Lena is in mourning because the Youngers love their children and do not want to lose another to poverty (Kappel 33-62). After Walter decides to accept the white association's offer to pay them in return to not to move into the neighborhood, Lena demands that he make his capitulation in front of his son, Travis. However, instead of accepting the money, Walter declares his pride in the six generations of his family that have lived in America (Kappel 127). Moreover, Ruth has decided to have the child, who will represent the family's seventh generation. As the Youngers get ready to move at the end, Lena applauds Walter's coming of age: "He finally come into his manhood today, [… k] ind of like a rainbow after the rain" (Kappel 130). The family has roots and will grow in the new neighborhood.