John Berryman was an American poet best known for his innovative contributions to confessional and autobiographical poetry, particularly through his influential collection 'The Dream Songs.' His work is characterized by a deeply personal and psychological exploration of identity, mental illness, and existential themes, which connect to the broader movement of confessional poetry that emerged in the mid-20th century. Berryman's blending of autobiographical elements with fictional narratives allows readers to engage with his inner struggles in a unique and impactful way.