Final answer:
The introduction of realism in the early twentieth century may have overshadowed the emergence of great American playwrights like O'Neil and Wilder.
Step-by-step explanation:
The introduction of realism in the early twentieth century may have overshadowed the emergence of great American playwrights like O'Neil and Wilder. Realism is a literary movement that sought to depict life as it is, without idealizing or romanticizing it. American playwrights like Eugene O'Neill and Thornton Wilder were important figures in this movement, creating plays that portrayed ordinary people and their struggles.