Kate Warne

Kate Warne (1833 – January 28, 1868) was an American law enforcement officer. She was known as the first female detective, in 1856, in the Pinkerton Detective Agency and the United States. 
She played a key role in helping then President-elect of the United States Abraham Lincoln travel to Washington, D.C. safely during the alleged Baltimore Plot (the plot to kill Lincoln in Baltimore, Maryland) in 1862. She was born in Erin, New York.
Warne died of pneumonia in Chicago on January 28, 1868.