Bureau of Military Information (BMI)
Peter A. Taylor ©
As given to the Stonewall Jackson Civil War Round Table,
Clarksburg,WV on February 8, 2005
Much of the research dealing with Military Intelligence during the Civil War was limited to first-hand accounts that were written after the war by various individuals claiming to be spies for the Union and Confederate armies. Many of these stories, today, are considered
fictional accounts rather than factually relating the events of the Civil War. In 1959 Edwin C. Fishel, while working in the US Archives, stumbled upon a stash of sealed documents. These documents were the actual reports that were compiled by the various agencies that made up the Bureau of Military Information and were the reports that were used to generate intelligence for Generals Hooker, Meade and Grant in the Eastern Theater of Operations. These newly discovered documents bring to life a part of the Civil War that has not been adequately researched. Tonight we will take a look at the evolution of a Military Intelligence system and see how this critical military branch was developed during the Civil War.
Personally, I spent over twenty-seven years in the United States Army as a military intelligence officer. In a military branch that is highly secretive and compartmentalized, I had the distinct fortune to serve in virtually every part of the military intelligence community. In Vietnam I served as a tactical intelligence officer, served in counter-intelligence (the Phoenix Program), operated agent nets, interrogated POWs and refugees, conducted both ground and aerial reconnaissance missions, and worked as a signal intelligence officer with the old Army Security Agency. I have served as an S-2 Intelligence Officer on the staff have been involved with the development of tactical intelligence studies, and the conversion of
raw data and information into workable intelligence for the commander. These experiences give me a broad insight into the scope of military intelligence collection and I hope will enable me to better define and explain how important these developments were during the Civil War.
When we speak of Military Intelligence, it includes these basicelements. (1) Enemy (2) Terrain, and (3) Weather. Today we take intelligence for granted but in 1861 the US Military did not have a specific organization that was tasked to gather information and analyze this data to provide the commander an estimate of enemy intentions and capabilities,
Before March 1863, intelligence collection and analysis was a rather haphazard affair. It was the responsibility of the individual commander to develop intelligence about the enemy. There was no organized "branch" in the military to handle intelligence and responsibilities for intelligence collection was widely dispersed. It was up the individual commanders to collect and evaluate information and data and turn it into intelligence.
Sources of information were numerous. One of the most important "branches" of intelligence collection was from the well-established Topographical Engineer Corps. These officers were
pulled from the best that the US Military Academy had to offer. The top three to five officers to graduate from the academy were offered commissions in the Topographical Engineers. They were top-notched engineers with a special ability to draw extremely detailed maps.
Their mapping duties brought them very close to enemy lines and sometimes required that they operate behind enemy lines to insure that the maps that they had drawn were accurate. Their individual talents enabled commanders to resolve one of the critical aspects of
the battlefield that of analyzing terrain. Some of the most noted general officers in the military to include Robert E. Lee were products of the topographical engineers. However, even this
"branch" offered little analysis for the commander in regards to the dispositions and capabilities of the enemy.
A second element of intelligence came from what we think of today as "signal intelligence". Before the outbreak of the war,the Signal Corps was another element that provided data to the field commanders. Since signal towers or sites had to be positioned, high above the ground Signal observers could visually see enemy troop movements and report them to their commanders. In some cases, signalmen would be sent to high places just to observe the enemy's movement, but their flags would not be used so that they could maintain their observation posts unobserved. Signalmen also played a role in intercepting enemy signals. Since all signals were visible, anyone in line of sight could "listen in" on the other 'fellows'
messages if he could decipher their code and could observe the transmission. These signalmen played a vital part in gathering intelligence on the enemy.
Along with the signalmen, aerial observers played a limited role in intelligence collection. While balloons had an advantage of allowing the observer to reach relatively great heights they were limited by wind, cloud cover and the ability of the observer to see and report
what was happening on the ground. Additionally, professor Lowe, one of the early pioneers of aerial observation, was not a soldier. He never developed the talent to accurately identify enemy forces that he did observe. One of the first demonstrated assents made by
Professor Lowe included a telegrapher in the basket and a telegraph wire leading to the ground. This capability provided not only observation but also instant transmission of information to the ground commander.
This was also an era of long distance communications using the telegraph. It would seem that tapping into the enemy's lines would be relatively simple and a telegrapher could intercept
dispatches the way that the National Security Agency (NSA) intercepts telephone calls today. We have these romantic images of telegraphers hidden in bushes under tapped telegraph lines listening to the enemy's conversations, but in reality this only happened one time during the war and it yielded the Confederates little information of value.
The principal means of gathering intelligence on the enemy was with the cavalry. Small groups of men would scout out the enemy's camps, locate their positions and report to headquarters. Unfortunately, neither side really understood that this was the primary mission of the cavalry and many commanders misused this asset turning them into mounted infantry rather than intelligence collectors. These scouts often performed espionage missions. During
Grierson's Raid through Mississippi, one of the reasons for his stunning success was the use of his "Butternut Scouts" to scout out the roads ahead and onfuse the enemy to his intentions. His scouts were dressed in Confederate uniforms and greatly assisted with his success in evading the enemy that was nipping close at his heals.
Another important source of information regarding the enemy was through the use of "spies". While there are some outstanding stories of espionage agents who operated freely in and out of the enemy camps, many of these post-war stories are now being debunked as
fiction. There were a few real `spies", and most human intelligence (HUMINT) was gathered from interrogating POWs and from deserters, refugees and runaway slaves. In the case of POWs most of the information that they were able to provide was general in nature; what we refer to today as tactical intelligence. Information that might be obtained included the unit that the individual was from, the name of the commander, approximate strength (etc.) but a lot of this information was extremely perishable and unless it was rapidly exploited, it was of little use. Another source was from deserters. Deserters were usually willing to tell everything that they knew in hopes of better treatment, but in some cases deserters were really plants by the enemy to provide disinformation on their real movements. Refugees were usually very talkative, but provided little real intelligence unless they had lived in the proximity of a
military camp. The best source of information of a HUMINT nature was from runaway slaves, especially if these slaves had been serving as an officer's servant in one of the camps. Slaves were also valued because of their intimate knowledge of the smaller roads and
Another major source of intelligence was local newspapers. There was a brisk business dealing with newspapers between the lines. It is said that Lee learned almost everything he wanted to know about Burnsides operations and McClellan's operations by reading
Northern newspapers. To combat this General Hooker imposed strict censorship on the newspaper reports that were sent from headquarters to Northern cities for publication.
In the Beginning!
The Civil War found the military much unprepared for operations of armies as large as those on both sides. One of the things that they had no concept of was the collection and analysis of military intelligence. There were no organizations set up to collect and disseminate information to field commanders and no national collection agency to even initiate intelligence collection. However, when the war started he was concerned with organizing some sort of "Secret Service". His problem was that the paymaster for the Union Army was a pro-southern officer, Joseph E. Johnston and the other senior person who would have paid spies was Samuel Cooper, so he had to carefully organize his spies without the knowledge of his
Scott's spies did provide some useful intelligence before the Battle of Manassas or Bull Run, but most of the information was not relevant to tactical matters. Therefore, by the day of the battle Scott could not provide McDowell with much useful information regarding the enemy. In fact the biggest intelligence coup that day was scored by the Confederates who had organized their own Signal Corps under the command of Porter Alexander. Alexander, using the techniques he had learned from Major (Doctor) Myers established a series of forward signal stations that relayed information from the front to his position on Signal Hill that allowed the Confederates to maneuver in face of McDowell's forces to met his turning movements
against their flanks.
With the elevation of McClellan to command the army of the Potomac, there was a significant change in the organization of the military intelligence services. McClellan, a railroad executive before the war, had extensive dealings with the Pinkerton Detective Agency.
This agency had been employed to investigate fraud and theft against the railroad. Alan Pinkerton had also scored a major coup by ferreting out the assassination conspiracy against President-elect Lincoln in Baltimore. So when his old friend McClellan moved to
Washington Pinkerton followed and set up one of the competing agencies referred to as the "Secret Service".
Pinkerton is often criticized for his poor performance in dealing with McClellan. He is especially vilified because of the overestimation of the strength of the Confederate forces facing McClellan on the Peninsula. However, in reality Pinkerton's agents were very good. They were reliable, Pinkerton seemed to find very talented agents who were able to penetrate the innermost workings of various Confederate Bureaus in Richmond, and his spies
provided very accurate information regarding troop strengths and movements. Where the intelligence system failed was in the overall analysis.
Pinkerton provided McClellan with a lot of raw information but there was no single agency to convert this information into intelligence and to analyze the information and present it in a coherent and useful manner. So information was pouring in from spies, signal corps officers, cavalry scouts and other assorted sources but no one was compiling the information in a tactical or strategic intelligence picture. This disjointed effort led to an information collapse and a lack of intelligence on the enemy and his movements.
When McClellan was finally sacked after Antietam General Burnsides inherited this broken system. He made no effort to improve the system and during his brief tenure as the commander of the Army of the Potomac, the intelligence picture remained murky and un usable.
Enter Joseph Hooker. Hooker saw that there was a serious problem on his staff as far as the development of tactical intelligence on the enemy was concerned. Meanwhile, his opposite, General Robert E. Lee was getting a superb picture of the Union army facing him by merely reading the newspapers that were being swapped along the front lines. Hooker was furious when he realized the extent that this information was getting to Lee. One of his first moves was to credential all newspaper reporters and to effectively censor their
dispatches. While this infuriated many of the members of the media, those who didn't play by the rules were throw out of camp and also lost their ability to report on the men and situations in the camp.
Hooker also fired Pinkerton and sent him packing. While this delighted some it did create some significant counter-intelligence problems at first for Hooker. However, his next "hire" proved to be a most remarkable one. On February 10, 1863 Hooker's Chief of Staff, General Daniel Butterfield convinced Colonel George Henry Sharpe to take charge of a newly created Bureau of Military Information.
Sharpe's, immediate supervisor was the Provost marshal General Marcena Patrick. Sharpe's official title was as Deputy Provost marshal of the Army of the Potomac.
George H. Sharpe was a lawyer by trade and he commanded the 120t New York Infantry regiment. Sharpe kept one of Pinkerton's best men on the staff with him, John Babcock. Babcock was a superb agent and his talents greatly influenced the abilities of the Bureau. Within ten days of Hooker's assumption of command the beginnings of an intelligence organization had started. One of the things that Hooker realized was that he needed to centralize the analysis of intelligence into one agency. Sharpe recruited his own scouts and
agents to work behind enemy lines but he was also able to glean information from signal corps assets, deserters, captured spies, cavalry scouts, and runaway slaves. All information about the enemy was at his disposal and he was able to use this information to develop a very good picture of the opposition.
By March 15, 1863 Colonel Sharpe was able to provide Hooker with a very detailed picture of General Lee's forces. Additionally he had directed the topographical engineers to survey every crossing of the Rappahannock and identify every ford that was capable of
supporting troop movements. He had also included a detailed analysis of the road nets in the area south of the river. Sharpe had identified the location of each of Lee's divisions and had
information on every brigade in Lee's army and sketchy information on three other possible brigades that might be operating in the area. He could positively tell Hooker that Longstreet's Corps was not with Lee and he was able to ascertain that D.H. Hill was no longer with Lee
but was instead in command in North Carolina. Additionally, Union signalmen had successfully broken General Lee's signal codes and were able to effectively read his "mail".
Less than one month later Sharpe's Bureau of Military Information had correctly identified all of Lee's 6 divisions and 26 of the 28 infantry brigades. He had developed an extensive Order of battle and had identified 116 infantry regiments. He also gave Hooker a very
accurate estimate of enemy strength, a first for the Army of the Potomac. Through captured reports, he was able to tell Hooker that Lee had 56,200 infantrymen present for duty in April. By the time that Hooker decided to make his move Sharpe had refined his estimates and was within 350 men of Lee's official count.
Sharpe would continue to direct the Army of the Potomac's Bureau of Military Information for the rest of the war. While there were many battles to fight, the AoP could rely on very good information about the size of the enemy and its location. While developing "leadership intentions" was still illusive, Sharpe and his agents were able to provide timely information to the Commanding General throughout the remainder of the war.
The Bureau of Military Information was indeed a remarkable innovation. General Hooker had the insight to realize that he could not run the army and be his own intelligence analyst. He need specialization to handle all of the information that was barraging the Commander. Robert E. lee never did develop his own specialized intelligence branch. Lee relied on his own instincts and the raw data that was provided to him. Lee played the traditional 19th
Century commander's role of analyzing information about the enemy and developed his own sense of intelligence awareness.
Used by permission of the Author. For any questions or comments you can contact Pete at