American author Mary Roberts Rinehart, also known as the American Agatha Christie, was born on August 12, 1876, and died on September 22, 1958. The Circular Staircase, Rinehart's debut mystery novel, introduced the "had I but known" narrative approach. Although the exact phrase does not occur in Rinehart's book The Door (1930), she is regarded as the creator of the "the butler did it" story device. As one of the first women to visit the front lines in Belgium during World War I, she also worked to share the tales and experiences of these troops. Mary Roberts Rinehart, who is now known as Rinehart, was born in Pittsburgh, Pennsylvania's Allegheny City. Her father was a frustrated inventor, and the family experienced frequent monetary issues throughout her youth. Mary was just 19 years old when her father committed suicide. She was trained to use her right hand because she was left-handed at a time when that was improper. She attended public schools, received her high school diploma at the age of 16, enrolled in the Pittsburgh Training School for Nurses at the Pittsburgh Homeopathic Hospital, and completed her training there in 1896.