Rinehart, Mary Roberts: - 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 Ella Roberts, who is now known as Rinehart, was born in Pittsburgh, Pennsylvania's Allegheny City. Olive Louise, Mary's sister who is four years Mary's junior, went on to become well-known as a children's book author and nationally syndicated newspaper columnist. 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. Her autobiography, titled My Story, was first published in 1931 and then rewritten in 1948.