The author's purpose in writing this novel is to explore and connect with his own sense of identity. This book is a tribute to the author's mother, but in being that, it is also an autobiography. James McBride's choice to tell his mother's story while he was growing up is also an opportunity to explore his story and to discover his identity through examining his mother's, as well as the experiences that he had in his youth.
The racial tension that exists between black people and white people was always obvious to McBride. He says that he recognized his mother's "contradictions" and the way that she kept herself from having a crisis of identity. These contradictions also intimately affect McBride's life as he grows up as a biracial child, and many of the experiences he shares in the book reflect his attempts to play out an identity crisis of his own.
In The Color of Water by James McBride, the subtitle of the book tells its purpose. The full title is The Color of Water: A Black Man’s Tribute to his White Mother, and that is exactly what the book is about. McBride’s purpose in writing is to tell the story of the hardships his mother faced as a white Jewish woman married to a black man in the 1940s. He also intertwines her story with his own story about being raised as an interracial child.
Along with the story being a tribute to his mother, McBride also wanted to tell his own story regarding the hardships he faced and emotions he had to deal with while discovering his true identity in a very large family. In The Color of Water, McBride discusses themes of racism, interracial marriage, finding one’s identity, and self-motivation.
The author's purpose is to tell the story of his mother, who was born Jewish and married an African American man in New York, and to relate the courage it required for her to have an interracial marriage and interracial children. The book, written with chapters that alternate between the story of Ruth (McBride's mother) and the author's own story, is a testament to Ruth's fearlessness in both the black and white worlds at a time when that was almost impossible. McBride writes of his mother's "nonchalance in the face of what I perceived to be imminent danger from blacks and whites who disliked her for being a white person in a black world" (page 8). Ruth, her son writes, was indifferent to this hostility. She was, however, largely unwilling to discuss matters of race or identity with her children, who were left to piece together their identities on their own. Nonetheless, her children grew up with a sense of their mother's power and pride and a sense of the complex way in which identity is constructed in America.
Ostensibly, if you believe the subtitle, the purpose of the book is to pay tribute to his mother, Ruth McBride. The story is centered around the way that his mother worked tirelessly to raise a huge family in very difficult circumstances. The story also uses episodes where Ruth recounts her own life and her own family, making the story even more poignant and powerful.
I would suggest that his purpose is also to simply tell what is a very compelling story as most memoirs are set up to do. McBride emphasizes the importance and use of education in all of his family members' lives, so one could argue that it is another purpose.