In 1856, a 23-year-old widow became America’s first female private detective. Five years later, she helped protect former US president Abraham Lincoln

In 1856, a young widow walked into Allan Pinkerton’s detective agency in Chicago looking for work. But Kate Warne was not interested in becoming a secretary, one of the few positions a woman might have been expected to seek at the time. She wanted to be a detective. Pinkerton eventually gave her a chance, beginning a remarkable career that would take Warne undercover in criminal investigations and, five years later, place her at the centre of efforts to protect President-elect Abraham Lincoln from a suspected assassination plot.

A Job Few Thought a Woman Could Do

Warne was reportedly 23 when she approached Pinkerton in 1856. Hiring a woman as a detective was highly unusual, but Warne argued that being a woman could actually be an advantage. She could enter social circles and gain the confidence of women in ways male investigators often could not. The strategy worked. Warne became recognised as the first female private detective in the United States and eventually headed Pinkerton’s female detective bureau. Her assignments required her to assume different identities. According to the Library of Congress, she once posed as a fortune-teller to extract information from a suspect.

She Befriended a Suspect’s Wife

One of Warne’s early successes involved money stolen from the Adams Express Company. Pinkerton suspected Nathan Maroney, who managed the company’s Montgomery, Alabama, office. Rather than interrogating him directly, the agency sent Warne to become friendly with his wife. The plan paid off. Warne gained Mrs Maroney’s trust, and she eventually led the detective to the location where the stolen money had been hidden, helping strengthen the case against her husband. But Warne’s most consequential assignment was still ahead.

A Suspected Plot Against Abraham Lincoln

In 1861, Allan Pinkerton was investigating security problems involving the Philadelphia, Wilmington and Baltimore Railroad when his team uncovered evidence of a suspected plot to assassinate President-elect Abraham Lincoln as he travelled through Baltimore on his way to Washington for his inauguration. Warne was sent undercover into Baltimore’s secessionist circles. Using identities including Mrs Cherry and Mrs Barley, she presented herself as a Southern sympathiser and attended gatherings where she collected information about the suspected conspiracy. Her ability to move through these circles without attracting suspicion became one of the operation’s greatest advantages.

She Accompanied Lincoln Through Baltimore

Warne’s role did not end with gathering intelligence. After Lincoln agreed to alter his travel arrangements, Warne bought sleeping-car tickets and accompanied Lincoln, Pinkerton and Lincoln’s friend Ward Hill Lamon on the overnight journey. As part of the cover story, she presented Lincoln as her sick brother who needed privacy. The train reached Baltimore in the early hours of February 23, 1861. After transferring across the city, Lincoln’s party continued towards Washington, arriving at around 6 am.

A Detective Who Changed What Women Could Do

Warne continued working for Pinkerton during the Civil War and eventually became superintendent of the agency’s female detectives. She remained with the organisation until she died in 1868. Her story is remarkable not simply because she helped protect a future president. In an era when detective work was considered a man’s profession, Warne recognised that society’s assumptions about women could themselves become an investigative advantage. What began with a 23-year-old widow asking for an unconventional job ultimately helped establish a place for women in American private investigation and put Warne inside one of the most dramatic security operations of Abraham Lincoln’s journey to the presidency.