The First Official Female Private Eye

Kate Warne is viewed by many to be the first female private detective in the U.S. Perhaps a better way to say it is, she’s the first official female private detective, as she was the initial woman hired by the established Pinkerton National Detective Agency, the nationally recognized private detective agency in the United States, which was founded in 1850.

But I say official because there were other gutsy, tenacious and creative women who conducted investigations prior to Kate.

Kate’s Tough and Talented Predecessors

There were women going back to the American Revolution who had the savvy to run reconnaissance as well as outwit, out-investigate and outmanuever their opponents. Women like Emily Geiger who, in 1781, stepped forward to be a messenger for General Nathaniel Greene who needed an operative to slip a message past the British to General Thomas Sumter. Emily, caught by the British while on her way to Gen. Sumter’s headquarters, ate the secret message, but had memorized its contents, which she later verbally related to General Sumter.

There’s also Prudence White who directed other women in her town to go undercover. Dressed as men, they conducted a lengthy surveillance, eventually surprising a British officer and retrieving secret messages he carried. Or the talented Patience Wright who hid secret messages inside her sculpted wax figures to aid the cause of the American Revolution.

Now let’s return to the first well-known private investigator in the U.S., Allan Pinkerton.

Pinkerton’s National Detective Agency


In 1850 (some sources say in the early 1850s), Allan Pinkerton and a partner established the North-Western Police Agency outside Chicago, one of the first private detective agencies in the U.S. As I well learned starting my own private detective agency, it’s one thing to open such a business, another to successfully market it. Although there were other private detective agencies at that time, Pinkerton, a one-man marketing wonder, promoted the Pinkerton National Detective Agency to becoming the premiere detective agency in the U.S. Didn’t hurt that he had connections in high places: At the Rock Island and Illinois Central Railroad for which Pinkerton had previously investigated numerous cargo theft cases, he had the support of the president of the company, George McClellan, later Major General George B. McClellan in the Civil War, and McClellan’s attorney, a young lawyer named Abraham Lincoln. Both McClellan and Lincoln agreed to use Pinkerton’s private investigation services.

Kate Warne Demanded to Be a Private Detective

There is little biographical information about Kate Warne, although sources claim she was born in 1833 in New York, and her husband died soon after they were married. She had no children. Allan Pinkerton described her as a slender, brown-haired woman who, in 1856, responded to an ad for detectives at the Pinkerton National Detective Agency. Pinkerton presumed she was there to inquire about a clerical job. Later, he said that she demanded to be a private detective, and he eventually hired her for that role on August 23, 1856.

By 1960, Pinkerton had hired several more women to be detectives, calling them his “Female Detective Bureau.” Warne became the supervisor of the Female Detective Bureau.

She played a key role in numerous investigations. In 1858, she participated in the Adams Express Company embezzlement case in which an expressman, Mr. Maroney, was suspected of stealing $50,000 from the company. Warne, who was skilled using accents and wearing different disguises, befriended Maroney’s wife and through her, accrued evidence about his theft that eventually led to Mr. Maroney’s conviction (he was sentenced to 10 years in prison). Thanks to Warne, $39,515 of the stolen money was returned to the Adams Express Company.

Pinkerton and Warne often represented themselves as a married couple to gain entry to certain social circles and situations. Similarly, my husband and I, when we ran our private investigations agency for a decade, would sometimes work a case in tandem as a couple. For example, if we were hired to uncover a husband or wife’s possible infidelity, we might pose as a dinner couple at the same restaurant as the philandering spouse, or attend an event as a couple to observe who a spouse was with.

Warne Helped Thwart an Assassination Attempt on Lincoln

Perhaps Kate Warne’s most famous case was her role in helping foil an assassination attempt on President-elect Abraham Lincoln on his travels to Washington, D.C. for his inauguration. According to the Central Intelligence Agency’s website article “Saving Mr. Lincoln,” Warne accompanied Pinkerton and four other operatives from his agency to Baltimore where Pinkerton had heard a plot to assassinate Lincoln would take place. According to other sources, she both helped to coordinate the operatives as well as to devise a strategy for getting Lincoln safely from Baltimore to Washington, D.C.

Different sources refer to Lincoln’s fervent opposition to the investigators’ strategy, which required him to go undercover, because he didn’t want people to view him as cowardly. But Pinkerton, Warne and others had enough evidence of a plot to convince Lincoln to go along with their plan. In it, he played Warne’s invalid brother, whom she was taking by street car to Washington, D.C. Warne must have had an appealing, charming personality because this was one of several incidences in which she cajoled people to do her bidding. In this particular case, she convinced the  conductor to leave the back door of the street car open so her sickly brother could enter the compartment with privacy.

That night, as the carriage traveled to Washington, D.C., Warne, Pinkerton, another operative named George Bangs and a personal friend of the President’s, Warren Hill Lamon, took turns staying up all night to guard the President-elect. In a sense, she was one of the models for the future Secret Service.

Some think that the Pinkerton agency’s motto “We Never Sleep” originated from Kate Warne never leaving Lincoln’s side the entire night they escorted him to Washington, D.C. This trademark effected the term private eye.

A Possible Photo of Kate Warne

Considering she excelled in her profession as a private detective, often going undercover for cases, it’s not such a surprise that there are no known photos of her. I know PIs who specialize in undercover work and surveillances, and they take great care to not post photos, or have public pictures taken of them, to maintain their anonymity.

However, many believe there is a photo of her, in disguise as a Union solider, in the below photo (she’s the “man” standing behind Pinkerton, the bearded gentleman seated on the right):

Why do people think the soft-faced soldier is Kate Warne? She was known to have been traveling with Pinkerton at this time. The person has no facial hair, and the physicality matches Kate’s (slim, brown hair).

The End of Her Career

On January 28, 1868, Kate Warne passed away suddenly at the age of 35 from pneumonia. Pinkerton was at her bedside. She’s buried in the Pinkerton family plot in Graceland Cemetery in Chicago. Pinkerton is laid to rest next to her.

In his memoirs, Pinkerton credited two of his operatives for establishing the Pinkerton National Detective Agency as an efficient, honorable organization: Timothy Webster, an agent who was executed during the Civil War for espionage, and Kate Warne.

Were Pinkerton and Warne Lovers?

It’s been surmised by many that the married, family-man Pinkerton and the widowed Warne were clandestine lovers. They often posed as a married couple in their investigations, and in the only known photo of her she’s accompanying Pinkerton on a trip. Plus, he was at her side when she died, and they are buried next to each other in his family plot.

In the May-June 2008 issue of Harvard Magazine (“Sleuths in Love“) screenwriter-novelist Eric Lerner believes they were paramours and wrote a novel about their liaison titled Pinkerton’s Secret.


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