Respuesta :

It was most likely modernism that helped shape the American theater at the end of the 19th century. The modernism movement lasted from the late 19th century until World War 2.

Answer: modernism

Explanation:

Hi, the literaly movement at the end of the nineteenth century that helped shape american  theater was modernism.

Modernism fostered a period of experimentation in the arts from the late 19th.It was a radical approach that yearned to revitalize the way modern civilization viewed life, art, politics, and science.

It lasted until 1940’s, replaced by postmodernism wich is still ongoing today.