While there are other notable playwrights from that era, O'Neill stands out for:
* His groundbreaking work: O'Neill pushed the boundaries of American theatre with his experimental plays that explored themes of family, addiction, and the human condition.
* His critical acclaim: He won four Pulitzer Prizes and a Nobel Prize in Literature, cementing his legacy as a literary giant.
* His lasting impact: O'Neill's plays continue to be performed and studied today, making him one of the most influential American playwrights of all time.
Other prominent playwrights of the early 20th century include:
* Tennessee Williams: Known for his poetic and deeply emotional plays like "A Streetcar Named Desire" and "Cat on a Hot Tin Roof."
* Arthur Miller: Famous for his plays exploring social and political issues, such as "Death of a Salesman" and "The Crucible."
* Clifford Odets: Focused on realism and social commentary in plays like "Waiting for Lefty" and "Awake and Sing."
Ultimately, the "most famous" is subjective, but Eugene O'Neill's widespread recognition and lasting impact on American theatre make him a strong contender for the title.