A Raisin in the Sun is a play about an African American family's struggle to rise into the middle class. Everyone in the family has their own personal ambition, and the conflict in the play arises from disagreement over how best to use a sudden windfall—a $10000 insurance payment. Walter and Ruth are a case in point. Walter, ambitious and headstrong, wants to use the money to invest in a business with his friends; his wife, Ruth, on the other hand, has sided with Walter's mother, the head of the family, and wants to use the money to make a down payment on a house.
I think Walter's relationship with Ruth is like his relationship with his entire family—on the one hand, he views Ruth and her pregnancy as a weight that is dragging him down, but on the other, by the end of the play, he has come to understand that family is more important than personal ambition. The turning point comes at the end of the play. The mother has used the money to make a down payment on a house in a white neighborhood, and the community association has offered to pay them not to move in. Walter has decided that they should take the money, but when it comes time to sign the papers, he changes his mind. He realizes that the good of his family is more important than any personal ambition he might have.
In A Raisin in the Sun, Walter and Ruth are initially quite distant from each other. At the beginning of the play, Ruth asks Walter how he wants his eggs cooked. He replies that he'd like anything except scrambled, but Ruth goes on to scramble the eggs. This is a subtle hint at the nature of their relationship. Ruth knows that Walter is missing something in his life and that it is something that she cannot give him. Walter feels that Ruth is not supportive of his dreams. This drives a wedge between the two. When Ruth tells Walter that she is pregnant and planning to abort, he cannot deal with the situation and goes out to drink. The lack of support in their marriage is only amended near the end of the play when Walter tells Mr. Linder that his family is proud. The reader assumes that Walter has decided that his family comes first and that he will seek to have a better relationship with Ruth.