While all good stories have an element of mystery, things to be discovered by both the reader and characters during the course of a story, Edgar Allen Poe is credited as having written the first true mystery.
When he wrote "The Murders in the Rue Morgue" (1941) he introduced the first fictional detective as a main character in a story. Because of this Poe is considered the father of the mystery story. He wrote about the same fictional detective in similar novels like "The Mystery of Marie Roget" (1842) and "The Purloined Letter" (1845).
His stories focused on unraveling the mystery, using intellectual, and looking at the criminal's motivation. Poe was influenced by the early work of Charles Dickens.
YOUR INVESTIGATION: What was the name of Poe's first fictional detective?
ANSWER: Auguste C. Dupin