Spying, Espionage, and Intelligence During the Civil War
By Ethan O'Reilly

A Morse Telegraph

During the Civil War both sides quickly took advantage of spies and espionage. The Confederacy used spies from the beginning but the Union was quick to catch on and soon had their own network of spies scattered throughout the opposing side. Before the war, neither side trained people as spies so a lot of intelligence came from independent organizations. Because there was no guarded border it was easy for spies to slip across and infiltrate the other side without detection. It was almost impossible to identify a spy because America is the melting pot of the world, so people couldn't be told to look out for somebody who looked or spoke a certain way because both sides were very diverse. Telegraphs became very important during the Civil War because they allowed spies to communitcate with their own side quickly but they could just as easily be used to send false intelligence to fool the other side. Hot air balloons were also invented during the Civil War so that spies could observe and estimate the amount of enemy troops.

Unon Spies

The Union made use of escaped slaves by gathering any information that they had gathered before escaping. In the Union it was up to each general to hire their own spies. George McClellan was the first Union general to do so, when he decided to hire Allan Pinkerton and his intelligence agency. Ulysses S. Grant assigned Brigadier General Grenville M. Dodge to
Colonel George H. Sharpe
head the intelligence operations in the West. Dodge used civilian agencies to infiltrate the South and supply Grant with valuable information. Grant later assigned Colonel George H. Sharpe to head intelligence and espianage in the East. Sharpe used mainly female spies who could go undetected in the South, and he managed to give very precise estimates of troop numbers. Northern politicians involved in the war also made good use of spies. Lafayette Baker started off by working for General in Chief, Winfield Scott, and later for Secretary of War, Edwin Stanton. Baker managed to catch a great number of spies in Washington and he was later asked to head the search for Lincoln's assassin, John Wilkes Booth. The Union also made use of the first ever double agent in American history, Timothy Webster. Webster pretended to work for the Confederate Secretary of War, Judah P. Benjamin, while really reporting to Pinkerton but he was caught, and despite Lincoln's attempts to negotiate his release, he was hanged in April of 1862. The North started off with no coordinated intelligence operation but still managed to gather all of the information that they needed.

Pinkerton's Agency

Allan Pinkerton was a Scottish immigrant who started a civilian run detecetive agency which later turned into an intelligence agency during the Civil War. Pinkerton called his agency the United States Secret Service and it became the foundation for the Secret Service we know
Allan Pinkerton
today. Pinkerton spent most of his time working for George McClellan and constanty overestimated enemy troop numbers which encouraged McClellan to constantly run away from smaller forces. These exagerations tended to come from untrustworthy criminals he hired or escaped slaves who were too scared to have actually gotten accurate intelligence. An example of Pinkerton's incompetance was during the Peninsula Campaign when he told McClellan that Robert E. Lee had 200,000 men when in fact he only had 85,000 men. In addition to working as spies, his agency aso helped find enemy spies in Washington. They managed to stop an attempt on Lincoln's life in 1861 as well as capture Rose O'Neal Greenhow who was in a relationship with Senator Henry Wilson and was leaking information to the Confederacy.

Confederate Spies

The Confederates created the Special and Secret Service Bureau, run by William Norris, to direct intelligence and espionage operations. From the start of the war the Confederates had an extensive spy network throughout Washington. The confederates were the first to start using mines and torpedoes by having agents plant them in front of advancing troops or ships
John Letcher
. They developed a type of torpedo, called the Coal Torpedo which was disquised as coal and placed in a fuel storage depot by an agent, where it would then go on ships or trains and explode causing a devastating chain reaction. The Confederates would also have their men captured in order to spread fales information to the Union. James Harris, an actor and spy told Lee of troops advancing on him when he invaded the North, which helped prepare Lee but in the end only destroyed his army because based on this information he decided to head towards Gettysburg. Jacob Thompson, another important spy funded a Northern peace group called the Knights of the Golden Circle, in hopes that the North would decide to stop the fighting. He also tried to free a number of Confederate prisoners near the Canadian border as well as try to burn New York City by setting hotels on fire. Thompson was also the one who gave John Wilkes Booth the plan to capture Lincoln, which ended in Lincoln's assassination. John Letcher, a former congressman created a spy network in Washington during the April of 1861, and hired Thomas Jordan who was a pro-south West Point graduate and Rose O'Neal who was involved in Northern politics but favored the South. The South also used cavalry as scouts, including John Singleton Mosby and J.E.B Stuart. The South had a much more organized spy network than the North.

Elizabeth Van Lew
Women as Spies

Women were the ideal spies because Neither side suspected them, even though both sides used them to great success. Elizabeth Van Lew was a pro Union woman who lived in Richmond and asked to care for the Union prisoners so that she could send the North any information that they had. Van Lew also got her former slave, Mary Elizabeth Bower, a job as a servant to Jefferson Davis, and together they managed to gather intelligence for the Union. Emma Edmonds joined the Michigan army by pretending to be a man and gathered information for them by saying she was pretending to be a woman. The actress Pauline Cushman also worked as a double agent for the Union. Rose O'Neal Greenhow was a Confederate spy in Washinton who managed to warn the Confederacy of the Union advance on Manassas, which prepared them and may have been the reason that they managed to win Bull Run. Belle Boyd became a valuable spy to "Stonewall" Jackson, like when she told him that the Union men occupying Front Royal, VA were preparing to burn the bridges and supply depot before he attacked, and because of this he got there in time to stop the Union. Boyd was arrested on July 29, 1862 and was set free a month later because she was a woman, and she continued to act as a Confederate spy.


Before the Civil War spying was never considered part of the art of war but during the Civil War both sides learned just how important it is. At the start of the war the South took more advantage of spies but later the North started using them just as much. In the North it was up to each general to hire their own spies but the main intelligence agency was the United States Secret Service, created by Allan Pinkerton. In the South, the Special and Secret Service Bureau was run by William Norris. Both sides learned that Women were the best spies because nobody ever suspected them so they both started recruiting them.

This link will bring you to a very interesting discussion on Civil War spies and espionage.


ElizabethVanLew. 26 June 2010. Wikimedia Commons. 29 May 2012. <http://commons.wikimedia.org/wiki/File:ElizabethVanLew.jpg>.

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George H. Sharpe. 21 October 2011. Wikimedia Commons. 29 May 2012. <http://commons.wikimedia.org/wiki/File:George_H._Sharpe.jpg>.

Mathew Brady. Hon. John Letcher, Va - NARA - 528418. 23 October 2011. Wikimedia Commons. 29 May 2012. <http://commons.wikimedia.org/wiki/File:Hon._John_Letcher,_Va_-_NARA_-_528418.tif>.

Spying in the Civil War. A&E Television Networks, LLC. 27 May 2012. <http://www.history.com/topics/civil-war-spies>

Vanderford, Chad. "Espionage during the Civil War." Encyclopedia of American History: Civil War and Reconstruction, 1856 to 1869. New York: Facts On File, Inc., 2010. American History Online.Facts On File, Inc. Online. <http://www.fofweb.com>.

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