Allen Pinkerton, founder of the Pinkerton Agency, and wild west frontier lawman, is the subject of this post.
Old west legend Pinkerton comes to Illinois from Glasgow, Scotland, and starts out as a barrel maker. Allen Pinkerton, brother of Robert Pinkerton, becomes Chicago's first police detective in 1850 after serving a stint as a deputy sheriff for Kane County Illinois.

The full name of the Pinkerton Agency was Pinkerton National Defense Agency but this wasn't the original name of the first detective agency in America. The wild west legend Pinkerton had started the law enforcement agency with a partner by the name of Edward Rucker and they'd called the venture the North-Western Police Agency.
To become a detective the lawman needed first to become a spy. Pinkerton began learning the art of undercover investigating and of surveillance espionnage. Allen Pinkerton's undercover alias was Major E.J. Allen. He would go on to train his employees in the art of espionnage and "shadowing" criminal suspects became and remains a common detective practice.
Pinkerton is credited with forming a type of law enforcement agency that would be used as a format for many of the future police foundations such as the US Secret Service, and the FBI.
While lawmen like Pinkerton were highly sought out by people who wanted to rid the wild west of criminal gang members such as train robbers, their services were oftened seen by the working class cowboys, farmers, miners, and others as authoritarian agency doing the dirty work of tyrrant money makers and government officials.
Ironically a good spy needs to be a good liar. Same could be said of a good lawyer. A good liar eventually bites his own tongue and gets caught in his lie. Pinkerton died as a result of a self inflicted wound to the tongue. The old west legend Pinkerton tripped and fell on a Chicago sidewalk and bit his tongue. He later died of complications from this self inflicted wound.
Allen Pinkerton also found the time to write several books on his exploits of the old wild west frontier lawmen.
See an extended version of the Pinkerton story.
Old west legend Pinkerton.