Since Sylvia Plath's death in 1963, she has become the subject of a constant stream of books, biographies, and articles. She has been hailed as a groundbreaking poet for her starkly beautiful poems in Ariel and as a brilliant forerunner of the feminist coming-of-age novel in her semiautobiographical The Bell Jar. Each new biography has offered insight and sources with which to measure Plath's life and influence. Sylvia Plath Day by...