In answer to someone who thought the play’s ending was a happy one, Lorraine Hansberry retorted: "I invite him to come live in one of the communities where the Youngers are going!" But cannot the ending, in some measure, be seen as happy? Or at least as promising hope or greater strength for the Youngers as a family?

In rejecting the idea of a happy ending, Lorraine Hansberry was both encouraging readers and viewers to understand her play within the broader context of social changes in the 1950s and emphasizing that she did not intend the play as a conventional melodrama in which the loose ends are neatly tied up. The play is within the realm of realism in that many of the questions that arise in the play remain unanswered, and many of the conflicts remain unresolved. The single act of moving to a safer neighborhood would not answer or resolve all those things.
Regarding the specific issue of African American families living in white neighborhoods, Hansberry drew on her own and her family’s experience in Chicago’s Washington Park neighborhood. She wrote of this part of their lives in her autobiography, To Be Young, Gifted, and Black. In addition, attacks on black families in such situations were far from uncommon and sometimes violent. One especially well-known instance was the 1951 experience of Harvey Clark and his family in Cicero, Illinois, which required the National Guard to remove up to 5,000 whites who attacked their apartment building (Bell).
The area of where the play offers the greatest optimism is in the family dynamics among the Youngers and possible career moves. In particular, Walter’s taking a stand against Lindner’s offer shows his growth as an adult. He finally understands that his responsibilities encompass much more than providing for his family financially. While we do not learn about a career change, it seems likely that his entrepreneurial goals of business ownership will develop. This would be consistent with actual changes in the 1960s, which stemmed in part from affirmative action programs that provided entry points for businesspeople of color. Even if he stayed in the same or a similar job, his wages would probably have increased, as that was an economic trend in the 1960s.
The possible positive changes are most likely for Beneatha, Travis, and the new baby. Beneatha’s plan to finish medical school and become a doctor, as well as her interest in doing service work in a newly independent African nation, both are realistic in light of developments in the 1960s. Desegregation of medical schools as well as of hospitals encouraged African Americans to study medicine, although the number of black physicians increased slowly. Beneatha’s idealism might have led her to enroll in the first class of volunteers in the Peace Corps, established in 1961, through which African Americans were posted in African nations.
Bell, Jennifer. Hate Thy Neighbor: Move-In Violence and the Persistence of Racial Segregation in American Housing. New York: NYU Press, 2013.
https://books.google.com/books?id=qHbrgY2m2xEC&dq=1950s+housing+integration&source=gbs_navlinks_s

https://www.ama-assn.org/about/ama-history/history-african-americans-and-organized-medicine

https://www.nap.edu/read/9719/chapter/10