Civil War Spies: Belle Boyd

Belle Boyd got her start as a spy in Martinsburg, Virginia, at the age of 17. In 1862, the "Cleopatra of the Secession" obtained - and risked her life to deliver -- information that may have been pivotal to the outcome of the Battle of Front Royal.

Civil War Spies: Allan Pinkerton

Allan Pinkerton fell into detective work when he discovered a gang of counterfeiters in Illinois. In 1861, he helped thwart a plot to assassinate Abraham Lincoln, which may have led Lincoln to later tap Pinkerton to organize the first Union espionage.

Mata Hari, Sinister Salome?

Mata Hari was an exotic dancer and a courtesan, but today she's known more for her work as a spy. In this podcast, Katie and Sarah take a look at the extraordinary life of Mata Hari -- and whether the French intelligence community used her as a scapegoat.

During World War II, Axis and Allied powers struggled to discover the enemies' information while hiding their own. Tune in to this HowStuffWorks podcast to learn how the Navajo code talkers turned the tide of World War II.