Playwrights who experimented with adding thoughts and feelings to realistic drama in the 1920s and 1930s included

During the 20th century, experimenting a drama is being vital. Eugene O'Neill is the most praiseworthy dramatist in the 20th century. He experimented dramas with dramatic forms and methods of production.  Based on my research he worked with the Provincetown Players. 

A) His father was probably dead,so searching was pointless