- Isadora Duncan was an influential early 20th century dancer who helped establish modern dance as a new American art form. She rejected rigid, formal dance training in favor of more natural, free-flowing movements. - Duncan's unstructured, free-flowing style liberated dance from its traditional rules and emphasized natural, improvised movements inspired by nature, ancient Greece, and other cultures. - Her revolutionary approach to dance had a significant influence on the development of modern dance in America.