American poet, memoirist, and actress Maya Angelou wrote several volumes of autobiography that explore the themes of economic, racial, and sexual oppression. She is perhaps best known for her autobiographical work "I Know Why the Caged Bird Sings" (1969). The book garnered critical acclaim and a National Book Award nomination. It is the first of Angelou’s six autobiographies and is widely taught in schools. But because of its themes, it has faced controversy.