Much of Kate Warne’s life is shrouded in mystery, which is fitting considering she was America’s first female detective. Born in New York and widowed young, the slender, brown-haired Kate was in her early twenties in 1855 when she walked into Allan Pinkerton’s office and told him she wanted a job as a detective. The Scottish-born Pinkerton, himself America’s first private eye, was caught off guard that a young woman was applying for the position, but despite the lack of precedence for female agents, he decided to hear her out. Kate argued that a female detective would be an asset to Pinkerton’s work, since a woman would be able to go places and get information in ways a man couldn’t. After spending a night thinking about it, Pinkerton decided to hire her.
Pinkerton never regretted his decision, and Kate became one of his best agents. Pinkerton described her as “an intelligent, brilliant, accomplished lady” who was an “invaluable acquisition to [his] force” and said she displayed “tact, readiness of resource, ability to read character, intuitive perceptions of motive, and rare discretion.” In fact, Kate proved herself so skilled and able that Pinkerton began hiring other women as well and made Kate the superintendent of the female department of his agency. Pinkerton’s female detectives were usually charged with forming friendships with the wives and girlfriends of suspects to get them to confide information about the crime, so Kate did that . . . and much more.
Using a wide variety of aliases and disguises, Kate was involved in solving numerous cases, including bank robbery, embezzlement, poisoning, espionage, murder, and beyond. Her best-known case involved working with Pinkerton to save the life of president-elect Abraham Lincoln from the assassination attempt of the so-called Baltimore Plot. After Pinkerton learned of the possible plot, he sent Kate to Baltimore to disguise herself as a wealthy Southern woman and gather information. Then, when Lincoln passed through Pennsylvania by private train on his way to his inauguration, Kate was in charge of securing some sleeping berths at the back of a public train, which would allow Lincoln to switch to the other train and make it through Baltimore without his would-be killers knowing. When it came time for Lincoln to change trains, they disguised him as Kate’s invalid brother, and then once they were on the train, Kate and the other agents stayed awake all night until Lincoln was out of danger.
Very little is known about Kate’s life. Almost all the information we know about her today comes from the books Pinkerton published detailing the cases his agency solved. Any other information and records Pinkerton had relating to Kate were most likely lost when Pinkerton’s archives were destroyed in the Chicago fire of 1871. Many people speculate that Kate, in addition to being one of Pinkerton’s favorite agents, was also his mistress, but Pinkerton denied the claim. Kate died from an unknown illness on 28 January 1868 at age 35. Pinkerton stayed by her side and then had her buried—not far from where he would later be interred—in a section of his family plot reserved for special employees.