Your question makes reference to the themes of this play, and in my opinion there are there main themes: the dreams that the family have, the fight against racial discrimination and lastly the importance of family.
All the family have their own separate dreams - Beneatha wants to become a doctor for example. These dreams are something they fight for throughout the play, and they face many barriers in achieving these dreams. The characters undergo varying emotions of happiness and depression depending on how their dreams are faring. By the end of the play, they realise that the most important dream out of all of their dreams is the dream of having a family house because it will unite the family. The title of the play refers to a poem by Langston Hughes where he talks about dreams that are forgotten or put off - he wonders if they shrivel up like a raisin in the sun.
Secondly, an obvious theme of the play is the fight against discrimination. From the start of the play, with references to racially motivated attacks, it is clear that this is a dominating theme throughout the play. Mr. Linder, of course, is the character in whom we find this racial discrimination most clearly defined. His bribe to persuade the Younger family not to move into the all-white neighbourhood does threaten to pull the family apart by challenging their value base. However, the Younger family eventually respond with unity and defiance, perhaps suggesting that the way to combat racial discrimination is not to let it go unchecked but to stand up with dignity and assert your rights.
Finally, the play talks about the importance of family. Despite the social and economic struggles that the Younger family go through in the course of the play, in the end they unite to buy their family house. Mama is the character who tries to teach the rest of her family the importance of family values, and Walter and Beneatha learn this lesson after their various traumas. Despite their conflicts, they still manage to unite to reject Mr. Linder's offer. Although they are still strong individuals, they manage to combine their individual dreams with the overarching family dream, putting the family's wishes before their own.