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Allan Pinkerton (1819–1884) -

When Scotsman Allan Pinkerton emigrated to the United States in 1842, he had no intention of becoming a detective.

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A new life -

Pinkerton was born in the Gorbals, a rough working-class area of Glasgow, on August 21, 1819. Seeking a way out of the crime and poverty belittling his home town, he jumped on a ship and sailed for New York. From there, he headed to Chicago and then onto Dundee Township where he built a cabin and started a cooperage, producing wooden casks, barrels, vats, and buckets.

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A chance encounter -

Once established, he sent for his wife, Joan. As a woodworker, he relied on a ready supply of timber. It was while out walking through a wooded grove looking for trees to make barrel staves that he stumbled across a band of counterfeiters.

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Banditti of the Prairie -

The collection of miscreants were very likely affiliated with the notorious Banditti of the Prairie, a group of loose-knit outlaw gangs that plagued the states of Illinois, Indiana, and Ohio in the early to mid-19th century.

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Crime-fighting career -

After observing the group's movements for a while, Pinkerton informed the local sheriff. A team of law enforcement officers arrived soon afterwards and arrested the fraudsters.

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Pinkerton National Detective Agency -

Pinkerton was hailed a local hero and later, in 1849, offered a position as the first police detective in Chicago. The following year he founded the private investigation firm that became the Pinkerton National Detective Agency.

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Private eye -

The agency's iconic logo—a large, unblinking eye accompanied by the slogan "WE NEVER SLEEP"—gave rise to the term "private eye" as a nickname for detectives.

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Contact with Abraham Lincoln -

The Pinkerton agency came to prominence in the 1850s hunting down outlaws and providing security for railroad companies. This led Allan Pinkerton into contact with officials from the Illinois Central Railroad, and one Abraham Lincoln, a lawyer who sometimes represented the company.

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Kate Warne, America's first female detective -

In 1856, Pinkerton hired Kate Warne as the agency's first female detective and, indeed, the first in the United States. She soon proved her worth, serving as an ideal undercover agent in situations where a male detective would likely be unmasked quickly.

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Pinkerton and the Civil War -

The Pinkerton agency earned its spurs during the American Civil War when its detectives started spying on Southern sympathizers as hostilities looked likely.

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A plot to kill Lincoln -

While gathering intelligence, Allan Pinkerton learned of a plot to assassinate president-elect Abraham Lincoln shortly before his first inauguration in March 1861.

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Gathering intelligence -

He discovered that a secret cabal planned to strike as Lincoln switched trains in Baltimore on his way to Washington, D.C.

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Foiling an assassination attempt -

Pinkerton alerted Lincoln to the alleged plot and, with the help of Kate Warne and other agents, arranged for him to secretly board an overnight train and pass through the city several hours ahead of his published schedule.

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Expertise in counterintelligence -

The counterintelligence work undertaken by the Pinkertons during the Civil War is comparable to the work done by today's US Army Counterintelligence Special Agents, of which Pinkerton's agency is considered an early predecessor.

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The agency post-war -

After the war, the agency refocused its efforts on running down train robbers, and scored several notable successes.

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The Adams Express Co. theft -

In 1866, the Pinkertons solved the US$700,000 Adams Express Co. theft perpetrated by the Reno Brothers Gang and the Jackson Thieves, a group of criminals that operated in the Midwestern United States during and just after the American Civil War. The amount stolen is equivalent to a staggering $13.5 million in 2025.

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Failure to capture Jesse James -

An early setback was the failure to bring to justice Jesse James. Pinkerton agents had been hired to track down the notorious Wild West outlaw in 1874, with Allan Pinkerton taking on the case as a personal vendetta. He later commented that James evading arrest was one of the biggest regrets of his career.

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Infiltrating the Molly Maguires -

The agency's reputation for carefully orchestrated undercover work was perfectly illustrated when Pinkerton agent James McParland infiltrated and helped to dismantle an Irish-American organization of activist Pennsylvania coal miners called the Molly Maguires.

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The disastrous Homestead Strike -

However, that reputation was severely tarnished in 1892 when the agency became involved in the Homestead Strike. Stemming from an industrial lockout by workers at the Homestead Steel Works in Pittsburgh, the strike culminated in a battle in which 10 people died and strikers defeated private security agents, including Pinkerton agents. The Pinkertons were escorted from the facility by armed union men. Their ignominious defeat led to the passing of the Anti-Pinkerton Act of 1893, which limited the federal government's ability to hire private investigators or mercenaries.

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Hunting Butch Cassidy and the Sundance Kid -

One of the Pinkerton's most celebrated operations was the dogged pursuit in the early 20th century of Robert LeRoy Parker and Harry Longabaugh, better known as Butch Cassidy and the Sundance Kid. The outlaw pair were part of the Wild Bunch, a gang responsible for a string of bank and train robberies.

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Inventing the mugshot -

The gang's faces were well known to the general public, the agency having developed the technique of taking photographs, or mugshots, of criminals while in custody and compiling a "rogue's gallery" of misfits. Both Butch and Sundance had previous run-ins with the law, so their mugshots were displayed prominently on reward posters distributed in 1902.

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Great Northern Railway Express train robbery -

Another member of the Wild Bunch, Harvey Logan, known as Kid Curry, was already on the agency's watchlist as one of two people suspected of holding up the Great Northern Railway Express train on July 3, 1901, in Montana.

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The Pinkerton sons take over -

Allan Pinkerton had died in 1884, but his sons, Robert (pictured) and William, ably took over the day-to-day running of the agency.

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Expansion across the US -

By 1906, the Pinkerton National Detective Agency had 20 different offices in the United States.

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Offices in major cities -

These included premises in New York (pictured), Boston, Chicago, and San Francisco. Pinkerton also had a presence in Montreal, Canada.

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Bigger than the army -

The late 1800s and early 1900s saw the Pinkerton National Detective Agency expand to the point where it boasted 2,000 detectives and 30,000 reserves—more men than the standing army of the United States.

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Diversifying its role -

Pinkerton operational procedure developed exponentially. The agency adapted to a changing world by modernizing and diversifying its role in crime-fighting management. Agents started to provide services encompassing surveillance, background checks, insurance investigations, and personal protection. Pictured is the daily log of a Pinkerton operative recording witnesses interviewed.

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Use of the lie detector -

The agency kept abreast of technology, such as advancements in forensic science. It was instrumental in the development of the lie detector. In this photograph, William Pinkerton is questioning the San Francisco chief of police while he is rigged to the apparatus.

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Incorporation of the agency -

In 1925, Allan Pinkerton's grandson, also called Allan, incorporated the agency and became its first president. He's pictured center in this photograph.

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Guarding Mona and Marilyn -

The year 1962 was notable for two events involving the agency. On August 8, uniformed Pinkerton agents were tasked with guarding the casket of deceased actress Marilyn Monroe, in Westwood Memorial Park, Hollywood. In December, Pinkertons escorted the 'Mona Lisa,' painted by Leonardo da Vinci, safely across the Atlantic Ocean after the French government had lent it to the United States to be displayed in New York City and Washington, D.C.

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Pinkerton today -

By the mid-20th century, the agency's crime-fighting duties had largely been absorbed by local police forces and the FBI. Today known simply as Pinkerton, it serves as a private security firm and comprehensive risk management platform.

Sources: (Pinkerton) (Britannica) (History.com) (EliteCEU)

See also: The history and nefarious fugitives of the FBI's Most Wanted list

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