Eugene O'Neill. He's the father of American drama and an influence on every playwright that followed him. There really was no American theatre prior to him and he basically took the innovations of Chekhov, Ibsen and Strindberg in Europe and expanded upon them within an American context and created the American theatre. The winner of 4 Pulitzers and the only American playwright to date to receive the Nobel for Literature, no one else is more influential.
In musical theatre, you might consider George M Cohan (actor, writer, singer, dancer, composer, lyricist, impresario) who was the first to create musicals that even vaguely resemble what we now consider musical theatre and Oscar Hammerstein II, who with Showboat and Oklahoma -- two of the most influential landmark musicals in history, if not THE two most influential -- is more responsible than anyone for the creation of the book musical that uses music and dance to advance the plot and inform character. Every composer, lyricist and book writer since owes him a debt.
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
[http://margochanning.broadwayworld.com/]
"The Devil Be Hittin' Me" -- Whitney
Updated On: 4/4/06 at 11:05 AM