What is the main problem in story sounder?

In the story "Sounder", the main problem is the racism that the family faces. The father, Nathan Lee, is accused of stealing a pig and is subsequently arrested and taken to jail. His son, David, is determined to prove his father's innocence and sets out on a journey to find the real thief. Along the way, David faces many challenges and obstacles, including the racism of the white people he encounters. The story ultimately ends with Nathan Lee being released from jail and reunited with his family, but the problem of racism is still present and unresolved.