The carrier of the report was Betty Duvall, a young friend of Greenhow. Duvall, dressed in a farm woman’s clothes and driving a cart, passed through the Union sentinels on the Chain Bridge across the Potomac in Washington, and stopped at a Virginia safe house, where she mounted a horse and rode to the outpost, near Fairfax County Courthouse. She told the officer in charge that she had an urgent message for Beauregard. “Upon my announcing that I would have it faithfully forwarded at once,” the officer later said, “she took out her tucking comb and let fall the longest and most beautiful roll of hair I have ever seen. She took then from the back of her head, where it had been safely tied, a small package, not larger than a silver dollar, sewed up in silk.” Within was the message for Beauregard.

On the advance toward Manassas, the Union troops had overrun the Fairfax outpost and found papers and maps that incriminated Greenhow. Her grand home, not far from the White House, was put under surveillance by Allan Pinkerton, who had been placed in command of the Union Army’s Division of the Potomac after the debacle at Bull Run. “I secured a house in Washington,” Pinkerton later wrote, “and gathered around me a number of resolute, trustworthy men and discreet women.” Pinkerton’s first major assignment was the capture of Rose Greenhow. One rainy night, wanting to peek into her parlor, he went to a high window, removed his boots, and stood on the shoulders of two operatives, “prepared to take notes of what transpired.” A man had entered—and Pinkerton recognized him as an officer assigned to the provost marshal’s office.

“Just at that moment I again received a warning from my supporters, and hastily jumping to the ground, we hid ourselves until the pedestrians had passed out of sight and hearing.” He climbed back on the men’s shoulders and saw the officer show Greenhow a map. The two left the room for more than an hour, returned “arm in arm,” and, with “a whispered good night and something that sounded very much like a kiss,” the officer left.

Rose O’Neal Greenhow and her daughter during her time at the Old Capitol Prison.

A week later, Pinkerton arrested Greenhow at her home and seized documents and personal letters that linked her to Senators Wilson and Lane, along with many other well known Washingtonians. She was charged with “being a spy in the interest of the rebels and furnishing the insurgent generals with important information relative to the movements of the Union forces.”

For ten months, she and several female friends were held in her home. Because she kept attempting to smuggle out messages, she was put in the Old Capitol Prison (now the site of the United States Supreme Court Building). She was released in June 1862 and sent through federal and Confederate lines to Richmond. After Greenhow’s capture, the cipher that Jordan had devised apparently was used for deceptive messages sent by Union officers. Writing about the cipher to Confederate Secretary of War Judah P. Benjamin, Jordan said, “Being my first attempt, and hastily devised, it may be deciphered by any expert, as I found after use of it for a time.”

The Confederates operated at least two other intelligence networks in Washington, both run by cavalrymen and probably set up by the Secret Service Bureau, a clandestine unit within the Confederacy’s Signal Corps. The bureau, a part of the Confederate War Department in Richmond, was commanded by Major William Norris, a former Baltimore lawyer. The Signal Corps ran the army’s semaphore service while the Secret Service Bureau oversaw a communications network whose missions included the running of agents to and from Union territory and the forwarding of messages from Confederate officials in Richmond to contacts in Canada and Europe.

One of the bureau’s most important tasks was the obtaining of open-source material, especially newspapers, from the North, primarily through sympathizers in Maryland, including postmasters. The newspapers provided information—and, occasionally, agents’ messages hidden in personal columns.

The delivery system—sometimes called “our Government route”—boldly relied on the U.S. mail along part of the way. One “mail agent,” a Marylander who lived near Washington, regularly drove his cart there, collected South-bound documents from network members, then hid the mail in manure that he picked up for his garden. Typically, an agent in Union territory wrote a letter, probably in cipher, addressed it to a specific person, such as “Secretary of War, Richmond, Va.,” and placed it in an envelope, which was then sealed and placed inside a second envelope. A U.S. stamp was put on that envelope, which was addressed to a collaborator, usually in Maryland. He or she would then continue the letter on its way by handing it to the first of a relay of mail agents for delivery to “signal camps” in Virginia.

Confederate mail supervisors established several accommodation addresses (as they would be called today) so that a suspiciously large amount of mail did not get delivered to one recipient. The system depended mostly on volunteers, some of whom made the enterprise profitable by adding smuggling to their espionage. There were also riverside farms where Southern sympathizers maintained simple signal systems. One of the signalers was 24-year old Mary Watson, who hung a black dress or shawl from a dormer window to warn boatmen across the river that Union troops were near.

Union officers assigned to investigating the rebel specialdelivery operation occasionally made arrests of mail agents, but the mail kept going through. Major General William T. Sherman was particularly incensed by the regular delivery of northern newspapers. Newspaper correspondents, he fumed, “should be treated as spies…and are worth a hundred thousand men to the enemy.” Yet, like other commanders on both sides, he planted false information in newspapers, well knowing that the enemy would read and perhaps believe the deception.

Many other riders, particularly a Confederate espionage group known as Coleman’s Scouts, were treated as spies.

Union interrogators, seeking information on the notorious Coleman’s Scouts, focused their attention on Davis. He knew that “Coleman” was the cover name of Captain H. B. Shaw, who had also been captured and was being held in a nearby cell. But when Brigadier General Grenville M. Dodge, a Union intelligence officer, demanded to know who and where Coleman was, Davis refused to talk. He remained silent even when Dodge threatened to hang him.

Davis, a 21-year-old infantryman, was a courier for Shaw. When he was hanged on November 27, 1863, he went into Confederate legend not as a courier, but as a spy. The legend has him say, “I would sooner die a thousand deaths than betray a friend or be false to duty.” He became “the South’s Nathan Hale,” one of many captives executed as spies by both sides. The number of suspected spies executed by both sides is not known because of the lack of records and the secrecy that surrounded most executions.

Because “spies” and “scouts” were used interchangeably, it is difficult to sort out “espionage,” which is the work of spies, from “reconnaissance,” which is the work of trained observers, such as cavalry scouts. Confederate General Robert E. Lee, for example, received a steady stream of intelligence from what would be called agents or spies today. In a report to Confederacy President Jefferson Davis, Lee said that “our scouts on the Potomac” had learned that a Union army was about to march because “three days’ rations had been cooked and placed in the haversacks of the men.” Another so-called Southern scout seemed more likely to be a spy because he “was able to converse with” Union troops to get an accurate estimate of the size of a deployment.

Lee’s greatest scout, Major General Jeb Stuart, won public fame as a dashing cavalryman leading audacious raids behind Union lines. But when he was killed in action in 1864, Lee gave him an epitaph worthy of a great spy: “He never brought me a piece of false information.”

 The Flamboyant Spy

Jeb Stuart