3. Allan Pinkerton (The Accidental Spy)
Popularly known as “the accidental spy” with the actual name Allan Pinkerton, he began his career as a savvy industrialist and later turned into a spy. Pinkerton somehow came across this vocation while trying to get rid of counterfeits using his detective skills. “The accidental spy” later found out that his detective skills and talents could be of more beneficial use.
This decision led Pinkerton in the year 1850 to establish a detective agency. This helped set his path to play the major role of spying on the confederacy while the civil war took place.