A modern reader of U.S. Civil War primary historical material will frequently encounter the terms “skirmish,” “skirmishing,” or “skirmishers.”  While the modern popular use of the word is to describe a small battle or fight, did these terms mean something else to period writers?  Actually, these terms referred to a particular type of combat, conducted by troops in an open order tactical formation, and primarily relied upon fire and skillful use of terrain to accomplish combat objectives.   This paper will provide an explanation of the pre Civil War military doctrine for skirmish combat, provide tactical examples of skirmishing, and demonstrate how open-order skirmish tactics evolved from an adjunct tactic.  Skirmish tactics became the basis of new methods of tactics replacing the double rank lines in response to technological challenges.  While some writers referred to skirmishers as “light troops,” “riflemen,” or by the French term “tirailleurs,” for simplicity this paper will use the term “skirmish” and “skirmishers.”^[1]

Most people have a mental image of Civil War combat being conducted by two lines of soldiers standing shoulder to shoulder in the open blazing away at each other at short range.  This image is reinforced by many paintings and drawings of the time period included in popular histories of the war.  The image is further reinforced for many by watching a civil war “re enactment” staged by modern hobbyists.  However, this image is only partly correct, as the massed formations were used relatively infrequently, primarily in the major battles.  Much of Civil War combat was conducted in skirmish formation, an open order method of deploying troops for combat. Additionally, there is evidence that prewar skirmish doctrine concepts of open order and use of terrain became influential in changing how battles were fought as the war progressed.  Combat tactics also evolved in response to the effects of technological change in the form of the widespread use of rifling in small arms and artillery, but largely followed the conceptual paths laid down before the war.

Military thought includes some elements of art and science, and some ideas need to be defined.  Since its founding in 1802, the United States Military Academy at West Point and its professors functioned as the school for land warfare officers in pre Civil War America.  Professor Denis Mahan defined two concepts that will be dealt within this paper.  First, the concept of  “minor, or elementary tactics” refers to the drill movements of soldiers and their formations.^[2]   Second, “grand tactics” refers to the concepts on how to use the drill formations to move and fight on the field of battle.  For the purposes of this paper, the first will be referred to as skirmish drill, and the second as skirmish doctrine or concepts.

While the U.S. Army had been using rifles as weapons for auxiliary troops since the American Revolution, the dominant weapon of the pre-Civil War infantry was the smoothbore musket.  The smoothbore musket with a grossly undersized ball allowed the soldier to load and fire his weapon three times per minute, even as the bore became clogged with black powder fouling.  The rifle, up until 1855, required a tight fitting projectile and could only manage one round per minute.  Military commanders previously had determined that the higher rate of fire was more important for the mass of the infantry, yet recognized the tremendous advantages of accuracy and range offered by the rifle.  But the poor accuracy of the smoothbore encouraged U.S. Army Ordnance along with developers in foreign countries to discover a solution.  In 1855,  by improving several French developments, the Army adopted a rifled musket and the Minie/Burton bullet.  This system allowed the speed of the smoothbore musket, but increased the accurate range of the musket from 100 to 400 yards.  Now the infantry had a weapon that combined the advantages of speed and accuracy, but no tactical system to exploit these advantages.

In 1854, knowing the potential capabilities of the rifle-musket then under development, Secretary of War Jefferson Davis (USMA 1828) ordered that a new system of tactics be adopted to overcome the possibility that “the new rifle [could] stop the advance.”^[3]   In the U.S.-Mexican War of 1846-1848, Jefferson Davis commanded the only completely rifle-equipped regiment of the Army and knew perhaps more than anyone the potential capabilities of a rifle musket in combat.  The rifle would require the basic elements of drill and maneuver control of the troops to be updated.  Secretary Davis had a problem that Mahan identified: “English military literature [was] quite barren in systematic works on most branches of the military art.”^[4]   The small prewar army  was at a disadvantage in there being little military literature in English to use in the education of the officers and other ranks in the art of war.  But it was an advantage in that a new system could be developed and distributed without having a body of knowledge to displace. Without a ready source of tactical doctrine, therefore, tactics would have to be originally developed, or the tactics of another major power could be adapted. 

Actually, the United States had been using the military systems and tactics of its Revolutionary War ally, France.^[5] American military theorists, such as Professor Mahan, preferred French systems because in their opinion French military practices were based on the extensive experience of the Napoleonic wars. These systems developed under an officer corps that since the French revolution was composed of men who earned their rank through skill rather than purchase like the British.^[6]  Mahan even partly credited American warfare experiences with influencing French skirmish doctrine by laying down “the foundation of the tactics of this day; a system that partly sprung up in the forests of America.”^[7]  Mahan summarized French skirmish doctrine as “a cloud of skirmishers, soon become expert marksmen, [which] harassed and confounded lines taught to fire only at the word of command . . . ”^[8]  Yet it is important to realize that French military doctrine came into U.S. usage through the filters of the American military translators and established American experience.  Undoubtably these filters served to make the doctrine distinctively American, but the undoubtable differences are beyond the scope of this paper.

The small prewar U.S. Army was not without drill and doctrinal works.  There were several existing works of military drill tactics in use in 1854 to build upon.  The first work on the details of skirmishing and deploying light troops was by Epaphras Hoyt of the Massachusetts Militia.^[9]  Hoyt published his manual in 1811, just before the second war with Great Britain, noting that the established regulations for the United States had neglected the subject.^[10]  Hoyt’s manual is very simplistic, designed for militia officers with no military experience, but the work covers basic concepts of deploying troops with good diagrams.  A hero of the War of 1812, General Winfield Scott, wrote his own Tactics in 1830 based upon his wartime experiences.  Scott’s Tactics served as the official drill and tactics manual of the U.S. Army until replaced by Hardee’s Tactics in 1855.  These works differed little in how to physically deploy skirmish formations.

Hoyt’s and Scott’s works provided the details of how to drill and deploy skirmishers, but little on how to use them effectively in combat situations.  Two other prewar works discussed conceptually how the commander could best employ skirmishers.  Henry Halleck, known in the prewar Army by the nickname “Old Brains,” wrote a treatise titled Elements of Military Art and Science in 1846 based upon his readings and translations of the works of Jomini, Napoleon’s memoirs, and other military theorists including Guibert, Clauswitz, and Archduke Charles of Austria.^[11]  In the smoothbore era in which wrote his work, he stated that skirmish troops would be mere “accessories,” employed for flank security and to annoy the enemy.^[12]   Halleck did detail a more extensive list of skirmisher missions in another part of his work, but believed that main battle would be fought by troops in lines or columns with smoothbore muskets.  Mahan, Professor of Military and Civil Engineering at the United States Military Academy for 1830 to 1871, assembled a series of his lecture notes on skirmishing and detached operations into a manual called Outpost in 1847.^[13]   Outpost was a manual for junior officers teaching them how to use skirmish troops and tactics to conduct detached operations, patrols, reconnaissances, convoys, and advanced guard operations.  The conceptual material in Outpost was certainly part of the education of cadet William J. Hardee (USMA 1838). 

Davis tasked now Lieutenant Colonel William J. Hardee with the mission of reviewing present drill and tactics systems and writing a new tactics manual for use with the new rifle musket.  Davis apparently personally supervised the project.^[14]  Hardee modified the existing skirmish drill (Scott’s), by mostly using translations of contemporary French manuals, and adding lessons from recent American experience.^[15]   Hardee’s manual was first published in 1855, and reprinted in 1860 and 1861 long with two Confederate editions with no significant revisions.^[16]

Hardee’s manual instituted several major changes to the skirmish drill and doctrine of Scott.  First, Hardee expanded the skirmish drill from a single company formation to the ability to use a battalion or regiment as skirmishers.^[17]  Scott only provided for one light infantry company in each regiment of ten companies to be trained in his skirmish tactics.^[18]  Hardee thus instituted a doctrine that allowed relatively large units to deploy in an open order formation, up to ten times the number of former practice.  A doctrinal change downward was also instituted with the concept of the “comrades in battle.”^[19]  The smallest tactical unit heretofore was the platoon of about forty men, but the “comrades in battle” were a four-man team, who were to fight and move together and support each other in the new skirmish system.^[20]  While Hardee’s system did not do away with the lines of battle, he did introduce the basis of a more decentralized, looser, and less rigid method of deploying troops in combat.  Hardee’s third major change in the drill system was instituting a great emphasis on the use and placement of skirmish troop reserves.^[21]  An unintended result of Hardee’s new drill system effectively changed troop control by both extending the physical distances over which an officer would have to command troops, but also placed a greater burden upon subordinate leadership to control these spread out formations and lead the “comrades in battle.”  General Sherman noted this problem in controlling the men in loose order during the war.^[22]

Hardee’s manual provided the pure mechanical movements of a skirmish formation. He also included some the doctrinal concepts that the soldiers needed to know to make them effective. How the troops conducted the fight, or the “software” doctrinal concepts behind the movements, determined combat effectiveness.  His professor of tactics at West Point, Denis Mahan, clearly had an impact on Hardee’s work in this area.  Mahan’s Outpost included many instructions on how skirmishers were to conduct themselves in combat.  Thus Hardee included in his drill manual several notes of conceptual instruction lifted from Mahan. In skirmish formation troops must use cover to their advantage, even if a straight alignment is sacrificed.^[23]  He also along with Mahan instructed that the troops should be calm and take their time to aim carefully to deliver fire accurately.^[24]  Hardee’s manual directed officers and sergeants to insure the soldiers fire at visible targets and estimate the range correctly.^[25]  Mahan emphasized officers required a “quick eye, presence of mind, and good judgement in taking up ground” to effectively employ skirmishers.^[26]  The old smoothbore tactics emphasized rate of fire only, as the smoothbore muskets were not likely to hit a target aimed at more than seventy-five yards.  The old tactics required the men to stand shoulder to shoulder in the open, while the skirmish drill directed them to seek cover, even at the expense of the regular alignment that was the trademark of the earlier line of battle formations.  In modern terms, Mahan taught that skirmishers accomplish their combat objectives through the skillful use of fire and terrain, rather than close combat and the bayonet.

With both a drill method and a conceptual doctrine developed and printed into books, it would only become useful if the officers learned and used the new ideas along with the new rifles.  Hardee used his appointment as Commandant of Cadets at West Point in 1856  to teach his new doctrine.^[27]  His former Professor of Military and Civil Engineering, Denis Mahan, was still teaching as well.  Thus since Hardee had used Mahan’s doctrinal ideas in his manual, the only “new” part of the system was to teach the improved drill itself to the cadets.  As virtually all the officers for the small regular army graduated from West Point, the regular junior officers would be quickly educated in the new system.  Significantly, while the militia did not have a systematic military education system, both Mahan’s Outpost and Halleck’s Elements were lecture notes published at the request of the New York Militia for use in educating officers.^[28]  Within units in the field, the further education of officers and sergeants was the responsibility of the commander.  Elisha Hunt Rhodes noted in his journal that he conducted classes for his replacement officers while in the trenches before Petersburg in 1865.^[29]  Rhodes now commanded the regiment that he first enlisted in as a private.  Yet he thought that book learning was important for his officers. It can also be inferred from the actual practice during the war whether or not the officers knew the doctrine by determining whether or not they actually used skirmishers as instructed in the manuals.

Equipped with a drill system to provide command and control of his skirmishers, and a doctrine of how to conduct a skirmish engagement, to what military purposes would a Civil War officer apply skirmish tactics?  Conceptually Halleck described in Elements the tactical missions of skirmishers to include: protecting the flanks of the main army, securing outposts, reconnaissance, deception of the enemy, and to ensure the safety of other troops by patrolling.^[30]  Mahan described in Outpost that in the attack or the defense “the infantry is divided into three bodies: an advanced guard, the main-body, and a reserve.”^[31]  The advanced guard shields the main body from surprise and allows the main body to maneuver to an advantage.  Mahan prescribed no more than a third of the force to be detailed to advanced guard duties.^[32]  Mahan and Halleck agreed that the actions of detachments required the deployment of skirmishers as the principal means of combat.^[33]  Fire, and not the bayonet, would be the instrument of the detachment.^[34]  The basic missions of a detachment were securing the main force from the enemy’s reconnaissance, and conducting reconnaissance against the enemy, were to be conducted in skirmish formations using skirmish doctrine and tactics.^[35]  The following paragraphs provide examples of how Civil War officers applied the skirmish doctrine in actual combat. 

Halleck’s description of the first mission for skirmishers was securing the flanks of the main body of troops.  Epaphras Hoyt included the best description and diagram of how to physically place troops for this mission in his work  (See figure 1.)^[36]   The march to contact is one of the most dangerous tactical maneuvers for the attacker.  Columns moving along

Figure 1.  Hoyt’s “Chain of Riflemen” deployment.

Note the      symbols indicate groups of four riflemen or skirmishers.  The source of the diagram is Hoyt’s Practical Instructions for Military Officers.^[37]

various axis of advance provide the opportunity for the defender to potentially isolate and defeat separate units.  Thus, the attacker must create security for his units by denying the enemy knowledge of the strength and axis of advance of the main body.  The use of skirmishers was critical in this role.  Skirmishers drove in the enemy’s cavalry and guard outposts before they could count the numbers of men and guns in the columns, fixed the enemy’s exact positions, found the flanks of the enemy’s defense, and tested by fire the enemy’s forces.   Mahan stated that skirmishers move quickly forward over broken or close terrain to seize potential choke points and obstacles ahead of the main body to ensure its secure passage.^[38]   In the very first major engagement of the war, Elisha Rhodes described how his regiment deployed five of its ten companies as skirmishers on the approach march to the first Bull Run battlefield.^[39]  Figure 2 is a diagram of Rhodes’ regiment deployment using his description.

Note how the regiment’s main body is shielded on all sides by skirmish lines.  Obviously Rhodes’ commander followed the textbook doctrine.

A second important use of skirmishers was to secure outposts so other troops could rest safely when the unit was not on the march.  Jones described a situation where two companies of his regiment were sent out to relieve the 21^st Iowa Infantry Regiment on an active fighting skirmish line so that the 21^st Regiment

Figure 2.  Rhodes’ regiment deployed as skirmishers in the approach march.