Final answer:
The provided text discusses the American poet Allen Ginsberg and his influential poem "Howl" but does not mention the author of "Casey at the Bat."
Step-by-step explanation:
The author who began his career working for the Harvard Lampoon and later wrote the famous poem "Casey at the Bat" is not mentioned in the provided text. However, the text provides considerable details about Allen Ginsberg, an influential American poet of the beat generation. Ginsberg is known for his groundbreaking poem "Howl", which he first read publicly in 1954. The poem and his collection were influential, addressing themes of anti-conformity, environmentalism, gay rights, and the American counterculture.
"Casey at the Bat," though, is a separate work by another author entirely, and it does not relate to Ginsberg's literary career or major works.