When Maya Angelou says “I know why the caged bird sings,” I think we ought to believe her, since she managed to write a whole book on the subject. I also think she must have had some important motives for writing the book since it does reveal her life story. But I think telling her story as a self expression was one of her purposes for the book. Aside from that, she wanted to depict the cultural situations she grew up in, as well as make social commentary about racial barriers. Probably the most obvious reason Angelou wrote the novel was to portray the events of her life and her memories of them.
This is apparent because few writers use their real name when writing stories in the first person, true or not. It also must be one of her motives because it contains some very personal, and potentially embarrassing information, particularly the event of her victimization by her stepfather. I imagine she’s actually quite proud of having overcome the difficulties she endured, so revealing her story was gratifying. Another goal which motivated her to write it was exposing the environment in which she grew up. The underlying purpose of this is to heighten the public awareness of how things were and are.
But this is not only for her own satisfaction, but as an example of how life was, growing up in black communities in general. She hopes to inspire people to move as far away from the original sources of those shortcomings as possible. Beyond that, another, more direct method of educating people which fit into Maya Angelou’s original plan was social criticism. Her satirical messages, although sometimes indirect, are very poignant. Actually, the most effective way to convey a concept related to personal issues is by example.
This is why she chose to use her own experience to appeal appealling personally to the reader, the end result being the same level of productivity which she intended. No doubt part of what made I Know Why the Caged Bird Sings such an influential piece of literature was the fact that Angelou was well motivated. She was motivated personally, to tell her story, to tell the stories of many other people summed up along with it, and to relate this to the inherent civil issues. And in addition to her drive she was intuitive enough to know the best way to achieve the desired end.