Allan Pinkerton was a Scottish-American cooper, abolitionist, detective, and spy, best known for creating the Pinkerton National Detective Agency in the United States and his claim to have foiled a plot in 1861 to assassinate president-elect Abraham Lincoln. During the Civil War, he provided the Union Army – specifically General George B. McClellan of the Army of the Potomac – with military intelligence, including extremely inaccurate enemy troop strength numbers. After the war, his agents played a significant role as strikebreakers – in particular during the Great Railroad Strike of 1877 – a role that Pinkerton men would continue to play after the death of their founder.

Pinkerton is a private security guard and detective agency established around 1850 in the United States by Scottish-born American cooper Allan Pinkerton and Chicago attorney Edward Rucker as the North-Western Police Agency, which later became Pinkerton & Co. and finally the Pinkerton National Detective Agency. At the height of its power from the 1870s to the 1890s, it was the largest private law enforcement organization in the world. It is currently a subsidiary of Swedish-based Securitas AB.