Intelligence and Espionage in the U.S. Civil War
According to the SpyCast website:
"Spies, cavalry, and telescopes were the traditional intelligence tools available during the Civil War, but there was also cutting edge high tech: the telegraph and the observation balloon. How did Civil War generals combine these to help make strategic decisions? As we observe the 150th anniversary of the Civil War, SPY Historian Mark Stout discusses this question with Professor William Feis of Buena Vista University, the author of Grant’s Secret Service: The Intelligence War from Belmont to Appomattox."