Founded in 1850, the Pinkerton National Detective Agency was the first of its kind in the United States. During the Civil War, Pinkerton served as head of the Union Intelligence Service. His most famous operation came in 1861, when his agents infiltrated a secret society in Baltimore, discovering a detailed plan to murder President-elect Abraham Lincoln as his train passed through the city. The intelligence allowed for a covert, nighttime rerouting of Lincoln's itinerary, safely delivering him t