Allan Pinkerton (1819-1884) was the father of many American police detection techniques and founder of America's most famous detective agency.

Allan Pinkerton was born in Glasgow on Aug. 25, 1819, the son of a police sergeant who was later wounded during the Chartist riots. Pinkerton himself became a Chartist and, fearing for his safety after participating in the turmoil, emigrated to the United States in 1842. He settled in a Scottish community at Dundee, III. He became an outspoken abolitionist, allegedly serving as the local conductor on the Underground Railroad.

While working as a cooper in Dundee, Pinkerton was instrumental in capturing a group of counterfeiters. After several private commissions in detective work, he was named deputy sheriff of Kane County in 1846. In 1850 he became the first detective on the reorganized police department of Chicago. He simultaneously organized a private agency, leaving public service soon afterward.

Pinkerton's agency, unlike the typical...