Allan Pinkerton (1819 -1884) was a Scottish detective known for creating the Pinkerton National Detective Agency, the first detective agency of the United States. Pinkerton first used "shadowing" (surveillance of a suspect) and "assuming a role" (undercover work). The detective stories he wrote were based in part on his own experiences and those of his agents. This first detective story is set in 19th century Alabama. An excerpt reads, "The officers of the company were completely at a loss. It was discovered beyond a doubt that the package had been sent from Atlanta. The messenger who received it bore an excellent character, and the company could not believe him guilty of the theft. The lock of the pouch was examined and found in perfect order, so that it evidently had not been tampered with. The messenger was positive that he had not left the safe open when he went out of the car, and there was no sign of the lock's having been forced."