O’Neill is one of the greatest American dramatists. He is a prominent dramatist of modern age. His parents were ardent Catholics. O’ Neill was established as the leading American dramatist. He was awarded Pulitzer prizes for Beyond the Horizon, Anna Christe. Despite some critical effort to debunk him Eugene O’Neill remains American’s outstanding playwright, the only one to win international fame and recoginition, and the Nobel Prize. All O’Neill plays are great tragedies but they are not tragedies of the conventional sort in the Aristotelian tradition. They are modern tragedies which strike at the very root of the sickness of to-day. The methods of the German Expressionists have also been effectively used by O’Neill in The Hairy Ape. The realistic techniques have not have been entirely abandoned but they been used to serve non-realistic purposes.