In Lorraine Hansberry's A Raisin in the Sun, how does the character Walter Lee evolve from beginning of the text to the end?

In Hansberry's A Raisin in the Sun,
Walter changes from the beginning to the end. In the beginning, Walter is a bitter black
man. He feels that life is not fair. He is angry because he cannot seem to get ahead. He
is dissatisfied with his job. Working as a chauffeur is demeaning to
him.

Walter lives in an apartment that is disappointing.
He is surrounded by strong women who are quite vocal. He and his wife Ruth
argue:

Ruth:
Eat your eggs, they gonna be cold.

Walter: That’s it. There
you are. Man say to his woman: I got me a dream. His woman say: Eat your eggs...Man say:
I got to take hold of this here world, baby! And a woman will say: Eat your eggs and go
to work...Man say: I got to change my life, I’m choking to death, baby! And his woman
say—your eggs is getting
cold!

When Walter is not
arguing with Ruth, he is arguing with his sister Beneatha or his mother, Mrs.
Younger.

Walter often escapes the arguing by hanging out
with his friends, drinking and dreaming.

Dreaming of owning
his own business, Walter gives Willy Harris his father's insurance money. When Willy
leaves town with the money, Walter becomes even angrier. He feels that he is a failure.
This leads to more drinking and bitter arguing.

To replace
the money he lost, Walter plans to sell the new house Mama has bought. Because Karl
Lindner and the white neighbors do not want the Younger family to move into their white
neighborhood, Walter is planning to sell out. He has fallen so
low.

When Mr. Lindner arrives, Mama insists that Walter
follow through with his deal of selling the house after explaining it to his son Travis.
Walter cannot sell out while looking at his son. He becomes the man of the house
finally. He makes the right decision. He informs Mr. Lindner that the Younger family
will indeed move into the new neighborhood. He promises to be good
neighbors.