Glaspell was highly regarded in her time, and was well known as a Pulitzer Prize-winning playwright. Her short stories were regularly printed in the era's top periodicals, and her New York Times obituary states that she was "one of the nation's most widely-read novelists."

Her early plays were in many respects as challenging and original as those with which O'Neill made his debut. Her concern with language as subject, with character as an expression of social role, with plot as a mechanism that may ensnare rather than locate the self, mode her very much a modern. In Trifles (1916) she developed a feminist critique of social role. In The Outside (1917) she staged a debate between the life force and a perverse celebration of death. In both plays silence becomes an eloquent expression of meaning. The Verge (1921) is an experimental work of considerable proportions, more daring in many ways than anything attempted by O'Neill. Though Inheritors (1921) is far more conventional it touched a contemporary nerve, questioning the nature and reality of American pieties. Long known only for a single play, Susan Glaspell now emerges as a significant figure in the history of American drama, a woman of genuine creative daring.