The American dream is based on socio-economic mobility and hope for the next generation.
In A Raisin in the sun, Mama (or Lena) wants to move from the cramped, dimly-lit, roach-infested apartment in the ghetto of New York City to the quiet suburbs of Clybourne Park where she can have a garden. Not only does she want this for herself, but she wants it mainly for Travis, her only grandchild and future Mr. Younger:
"Seem like God didn’t see fit to give the black man nothing but dreams – but He did give us children to make them dreams seem worth while." (1.1.206)
She wants him to have his own bedroom, instead of having to sleep on a couch in the living room.
The American dream is symbolized by the death of Mama's husband, Mr. Younger, and the insurance check that gives the family a chance to buy the real estate. Other symbols related to the dream are Mama's little plant that is barely alive from the meager light of the apartment. This represents Mama's hope, however small, that her husband's death can transform the family from renting to home-owning (from a culture of dependence on whites to self-sufficiency). Later, this plant will, of course, be planted in the naturally-lit garden in the yard at Clybourne Park.
Mama's dream is always there: it just moves (from the city to the suburbs and from hope to reality) and grows (from a droopy plant to a flowering garden).
For a writing assignment, Enotes gives sample outlines and thesis statements:
I. Thesis Statement: Mrs. Younger, Walter Lee, and Beneatha have cherished dreams. These dreams reveal a great deal about the nature of the characters’ longings which unjust societal expectations cannot destroy.
II. Mrs. Lena Younger’s dreams
A.Maintaining her family with dignity
1. Preserving the memory of the elder Mr. Younger
2. Enjoying a stable and secure family life
B. Having her own garden to tend to
1. The garden as representing aspirations held dear