Espionage: The Civil War

Erica Pandey

Intelligence played an important part during the course of the Civil War. Spies were used by both sides, and their information was useful in developing and finalizing tactics and strategy in the battles of the war. The Union and the Confederacy did not use highly effective methods in their attempts because the country was not accomplished in the area of espionage at the time. Skills relating to spying were not taught at West Point, a military academy, and the armies relied on civilians to obtain information. Spying was one of the two major areas of the war, the latter being nursing, in which women played a significant role. Though espionage was not advanced during the Civil War, this war showed the U.S. government the effectiveness of spies and our intelligence grew into a thoroughly evolved system.


The North had more of an organization to its espionage efforts due to Pinkerton's (see below) revolutionizing agency. Spies for the Union used disguise extensively in their assignments. They disguised themselves as peddlers, Privates, and even slaves. In addition, many Union spies were trained by Pinkerton, himself. Lastly, spies for the North had to pass a series of tests concerning their knowledge in weapons and war strategy. There were also practical tests such as shooting and riding. Though Southern spies were as successful as Northern spies, they were less trained. Almost all Southern spies were civilian volunteers. In direct contrast to the Union, the Confederacy did not use disguise at all in espionage. Instead, Confederate spies procured information much more simply. Spies usually just persuaded information out of Union officials or soldiers. The Union had more structure to their spying network, but both sides were amateur in this area during the Civil War.


Allan Pinkerton was the first man to develop a structured, sophisticated espionage system in the U.S. Pinkerton was born in Glasgow, Scotland in 1819. He fled from Scotland in 1842, to escape prosecution, and settled in Illinois. Pinkerton had had some involvement with investigation before establishing his own detective agency, the North-West Police Agency. Pinkerton was originally employed by railroad offices who needed his help in dealing with thefts. His association with the Civil War began with an investigation Pinkerton conducted on a group a Southerners that threatened a Northern railroad company. After this, he received a tip-off that there was a plan to assassinate (then President-elect) Abraham Lincoln, and warned Lincoln's advisers to increase his protection. As the war progressed, Lincoln assigned Pinkerton the job of organizing the Federal Secret Service. When George McClellan became the General of the Union army, Pinkerton sent spies on missions for McClellan because Pinkerton and McClellan were friends. McClellan and Pinkerton suspected Greenhow (see below) of espionage for the Confederacy and it was one of Pinkerton's agents who uncovered her. Lincoln eventually removed McClellan from his post, but Pinkerton continued with his job until the end of the war. His agency was renamed from the North-West Police Agency to the Pinkerton National Detective Agency. After the Civil War, the agency resumed their work with railroad companies. Pinkerton went on to write many books about his time as a detective in the war. Allan Pinkerton is remembered as the first man to intersperse espionage and war tactics in America.
Allan Pinkerton (right) with President Lincoln (center) at a Union camp.



Sarah Emma Edmonds disguised herself in order to spy for the Union. When she was fifteen, Edmonds left her home in Canada and journeyed to they United States. She created a fake identity of a young man named Frank Thompson, because jobs came easier for men, and enlisted in the civil war as Thompson. After serving as a private for a year, she decided to apply to replace an executed Union spy. Edmonds went to Washington D.C. and passed a series of tests, including recognizing weapons, riding, and shooting, that proved her ability in the field of spying. Her first assignment was to sneak into a Confederate camp to collect information about weapons that the enemy had. She disguised herself as one of the many slaves forced to perform grueling tasks, such as building walls around the encampment, and entered the camp. During her time there, Edmonds was able to note which guns and cannons the enemy were using. As part of her next mission, Edmonds took the form of an Irish peddler woman. She again slipped into a Confederate camp and reported to Union officials about the armies plans and movements. Edmonds continued her work as Private Frank Thompson until she had to resign because of malaria. After her resignation, Sarah Emma Edmonds gave up her identity as Thompson and started a family. In later years, when Edmonds applied for veteran status, her fellow soldiers were shocked to discover that Private Frank Thompson had really been a woman.

George Curtis joined the New York regiment as the Civil War started, but found that he was interested in the field of intelligence. He went on to become an agent for Pinkerton and one of the best at his job. In 1862, he completed a major assignment, in which he disguised himself as a merchant selling smuggled ammunition and traveled to the Confederate capitol of Richmond. On reaching Virginia, Curtis met with Confederate General Hill who not only passed him through to Richmond, but asked him to carry some Confederate supplies as well. In Richmond, Curtis met Confederate Secretary of War, Judah Benjamin, who agreed to take Curtis' help in the transportation of ammunition. For the remainder of the war, Curtis moved freely to and from Richmond, pretending to be a contraband merchant. He was able to give Pinkerton limitless information and was not suspected at all.

Mary Elizabeth Bowser was born a slave into the Van Lew house. The Van Lews were an affluent family who lived in Richmond. After the death of her father, John Van Lew, Elizabeth Van Lew, an influential abolitionist, freed all the family's slaves, including Bowser. Van Lew was also involved in pro-Union spying, and had created a network in Richmond. She asked Bowser work in Jefferson Davis' home, the Confederate equivalent of the White House. Bowser helped with some of the work at functions held by Varina Davis, wife of Jefferson Davis, and impressed Mrs. Davis. So, Bowser was promoted to the position of house maid. She worked mainly in the kitchen, preparing and serving meals. The fact that Bowser was a Black woman was to her advantage because she was ignored by the Davis family, making her job of obtaining intelligence all the more simple. The Davis' expected her to be uneducated and illiterate, when in truth Bowser had been given an education by Elizabeth Van Lew, and were careless around her. Bowser eavesdropped on Davis' dinner conversations with his military advisers. They spoke casually of troop strategy and Jefferson Davis left important documents lying loosely in his study. Bowser would note everything she could and relate all she knew to Elizabeth Van Lew, who would then pass this on to Union officials. Jefferson Davis eventually caught on that there was someone planted in his home, but he did not suspect Bowser until it was too late in the war for the Confederacy.

Philip Henson was born a Southerner in Alabama, but was shunned by his family due to his extreme Unionist beliefs. He began his work as a Union spy in 1862. Henson completed a variety of assignments throughout his time as a spy. Among these is an investigation in Vicksburg, Mississippi in which General Ulysses S. Grant asked Henson to gather information that would help Grant plan his attack on the city. Henson was suspected by Union officials many times due to his Southern heritage, but he proved himself time and again with his missions. After the Civil War, Grant asked Henson to conduct a "confidential and discrete" investigation of Abraham Lincoln's death which took Henson several years to accomplish. Though it is unknown what information Henson gave Grant through this inspection, it is said to have been of utmost importance.


Belle Boyd was born in 1844 in Virginia. In her time as a spy, Boyd escaped harsh interrogation and capture due to her femininity and beauty. She was known by the country of France as "Le Belle Rebelle" (The Rebel Belle.) In 1861, Boyd began her career. She would flirt with Union soldiers and coax key information about the army's strategy to report to Confederate officials. These methods were very effective because Boyd was so attractive. Boyd also carried supplies, weapons, and information between Confederate Generals Beauregard and Jackson. Perhaps Boyd's most important contribution to the Confederacy as a spy was her work in the Shenandoah Valley. She passed on intelligence of Union army weaponry and attack formations to General "Stonewall" Jackson. The Battle of Shenandoah After the war, Boyd became an actress and later gave speeches of her experiences in the War. A Video Clip about Boyd's life and Southern Spirit (NOTE: Though this video gives an interesting and accurate account of Boyd's life, there is Southern bias.)

Rose O'Neal Greenhow was able to be of great benefit to Confederate officials because of her standing in Washington D.C. She provided information about General McDowell's attack plan, which was key in turning the Battle of Manassas into a Confederate victory. Greenhow was married to a politician, and so she had high stature in Washington D.C. After her husband's death, Greenhow devoted herself to the Confederacy. She was elected by General Beauregard to led a network of spies in Washington D.C. Due to her husband's former position, Greenhow was able to gather information on the Union's plans for Manassas from Union government officers who were keen to impress her. She then related this intelligence to General Beauregard, who in turn used it to strategize the Confederate armies to oppose the Union forces and defeat them. The Union secret service placed Greenhow on house arrest, but she still spoke for the South, writing and publishing works that looked down upon the North's treatment of women. Greenhow recieved recognition from Jefferson Davis and P. G. T. Beauregard and was buried with military honors, when she died in 1864.
Sarah Emma Edmonds, in her disguise as Private Frank Thompson. This is the identity she used throughout her entire career as a Private, nurse, and spy for the Union Army.

Mary Elizabeth Bowser's gravestone, which honors her contributions to the Union army.

Belle Boyd, a female Confederate spy. She was known as the "Cleopatra of the Secession."

A book wriiten about Belle Boyd's life and accomplishments.

Rose O'Neal Greenhow seated outside her D.C. home, with daughter "Little Rose."

An illustration by Thomas Nast on Civil War Spies


  • Female spies were more useful and more popular than male spies.
  • Washington D.C. and Richmond were the most popular spy locations.
  • The act of spying was extremely risky and usually achievers did not receive any special recognition.
  • One usually became a spy after serving in the army for a while as a nurse or Private.
  • To become a spy, one was tested in knowledge of weaponry and war strategy. Ability to ride a horse and shoot a gun was also tested.
  • The Union was stricter in the qualifications for spies, while the Confederacy accepted almost all civilian volunteers.
  • Typical information passed on by spies concerned weapons and war strategy and tactics for either side.


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Frank, Lisa Tendrich. "Greenhow, Rose O'Neal." In Waugh, Joan, and Gary B. Nash, eds. Encyclopedia of American History: Civil War and Reconstruction, 1856 to 1869, vol. 5. New York: Facts On File, Inc., 2003. American History Online. Facts On File, Inc. Web. 17 May. 2009.

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