The importance of the Yiddish theatre to the modern American theatre has never been fully explored. In this work, you will see how the Yiddish theatre influenced the practitioners of the modern American Theatre, especially the Group Theatre and its denizens. The Group Theatre took full credit for the influence of Stanislavsky on modern American theatre, when in fact the Yiddish theatre first introduced the Russian master to the audiences of the Lower East Side of New York. Without the Yiddish theatre, the modern American theatre might never have evolved into what it has become today.