The Most Famous Female Spies of the Civil War: The History of the Covert Operations Conducted by Women Behind Enemy Lines

The Civil War’s most famous spy, the Confederate sympathizer Isabella Maria Boyd, is one of those people in American history who is as much myth as reality. Part of this is because she lived in an era that is still heavily imbued with a sense of nostalgia and myth, but her own personality is also heavily to blame, for she was what might in modern parlance be called a drama queen; since she was known for serial exaggerations in her work, historians are still trying to separate fact from fiction when it comes to her exploits. In the same vein, there was the matter of the people she surrounded herself with, many of whom needed a mythical figure to attach their last fading hopes for a Confederate victory to. They found such a person in Belle Boyd.

At the start of the war, the most formidable spy on either side of the conflict was a Washington widow named Rose O'Neal Greenhow. She was perfectly situated for espionage as a politically connected woman of extraordinary intelligence who had social reach and the desire to use every connection she had on behalf of a cause she believed in absolutely. In the first year of the war alone, she helped win a battle, ran a spy ring from inside her own house while under house arrest, and charmed her jailers in ways that allowed her to continue to pass intelligence from prison. 

The most effective Union spy of the war was a Richmond spinster named Elizabeth Van Lew, who ran one of the most successful espionage networks from a mansion on Church Hill in the heart of the Confederate capital. She communicated directly with Ulysses Grant, and she smuggled intelligence out of Libby Prison using methods so varied and inventive that the Confederate authorities who suspected her never fully figured out how she was accomplishing it. She recruited a woman she had freed from enslavement to serve as a domestic servant in Jefferson Davis' own household, placing an observer at the nerve center of Confederate executive decision-making.