'A Difficult Problem' is one of Green's short stories of crime and mystery. Anna Katharine Green was born in Brooklyn, New York, USA in 1846. She aspired to be a writer from a young age, and corresponded with Ralph Waldo Emerson during her late teens. When her poetry failed to gain recognition, Green produced her first and best-known novel, The Leavenworth Case (1878). Praised by Wilkie Collins, the novel was year's bestseller, establishing Green's reputation. Green wrote at a time when fiction, and especially crime fiction, was dominated by men. However, she is now credited with shaping detective fiction into its classic form, and developing the trope of the recurring detective.