Mary Roberts Rinehart (August 12, 1876-September 22, 1958) was a prolific author often calle the American Agatha Christie. "Dorothy B. Hughes, crime critic and novelist, says she 'has been and continues to be' the most important American woman mystery writer." She is considered the source of the phrase "The butler did it", although she did not actually use the phrase herself, and also considered to have invented the "Had-I-But-Known" school of mystery writing.