Born August 25, 1819 (Glasgow, Scotland)

Died July 1, 1884 (Chicago, Illinois)

Private investigator

Allan Pinkerton provided America with a national policing system at a time when there was little federal or state law enforcement. Credited as a reformer for popularizing private security, he focused primarily on crime prevention and investigation. During the American Civil War (1861–65; war in the United States between the Union [North], who was opposed to slavery, and the Confederacy [South], who was in favor of slavery), Pinkerton organized the first government-authorized secret service agency in American history.

The Pinkerton National Detective Agency was among the first...