How does Lorraine Hansberry make Walter's character a significant one?

Walter Lee Younger is the play's protagonist and is depicted as a dynamic character who experiences a significant change in his perception and outlook on life. Walter's character also creates conflict in the play, which drives the plot and leads towards the play's climax, where Walter redeems himself and maintains his family's integrity by refusing to sell Lena's home in Clybourne Park.
At the beginning of the play, Walter is portrayed as a passionate dreamer who feels stifled and held back by his family and current situation. Walter wishes to establish his own liquor business using Lena's $10,000 insurance check in the hopes that he will become financially stable and improve his family's living conditions. However, Walter feels as if everyone is deterring him from attaining his goals and realizing his dreams. Walter resents his wife and mother for initially overlooking his dreams and resorts to alcohol after Lena refuses to give him the money to invest in his liquor business. Walter's passionate appeals for realizing his dream create sympathy for his character, and the audience has sympathizes with his unfortunate situation. However, Walter is a complex man who comes across as insensitive, selfish, unintelligent, and shortsighted at times.
Walter's plight corresponds to Langston Hughes's poem "Harlem," which begs the question "What happens to a dream deferred?" Walter's depressed personality and lamentation influence his mother to finally give him the insurance money to invest in his dream. Unfortunately, Walter proves that he is inept at doing business as one of his shady partners steals the money. Walter responds by attempting to sell Lena's home back to the white neighborhood commission of Clybourne Park but hesitates to finalize the deal in the presence of his family. During this climactic moment, Walter experiences a change of heart and maintains his dignity by refusing to sell Lena's home. His courageous, honorable decision displays his maturation and character development as he makes the significant decision to foster his mother's dream. Overall, Walter Lee Younger's character serves as the play's protagonist, who makes several important decisions that affect his family's future and drive the plot of the play.