Civil War Terms

Learning about the Civil War can be difficult for someone new to the game, especially when it comes to military terminology. While many have casual familiarity with such terms as “company”, “regiment”, “brigade”, “division” and “corps”, they often use them interchangeably, seemingly choosing whichever word sounds “cool” to them in the moment, or, to give them more credit than that, simply confusing them because they are new terms to him or her. But these terms are not interchangeable, as cool as they may sound, and they have very specific meanings. These meanings vary from war to war and between nations, but we’re not concerned with those meanings. For our purposes here, the definitions of these terms will focus on the American Civil War-era military usage. This upload is designed to be one of many companion uploads to the main episodes of Addressing Gettysburg. This, is the Gettysburg Glossary.


A few things to note before moving on are that, when discussing numbers of soldiers, there are two types of figures given here: the “on paper” figures, meaning what the respective unit sizes should be if recruited and mustered into service at full strength, and the average numbers as they were at Gettysburg. So, when listening to episode 1, Antietam to Chancellorsville, for example, a brigade’s stated numerical strength would be somewhere in between the “on paper” numbers and the Gettysburg average. Disease, including infection, was the number one cause of death during the Civil War. These diseases were contracted in various ways. Some were a result of behavior, many more were a result of camp life, and others were the result of medical treatments.


Now a word about the Gettysburg average: All one needs to do is read two books on the battle of Gettysburg to find that no one truly agrees on the actual number of men involved. Throughout the fifteen and a half decades since the battle, scholars of the battle have looked at the numbers in an effort to come closer to a more realistic figure of totals. Some historians have the numbers at 95,000 Union soldiers against 75,000 Confederate soldiers. Some say 80,000 to 60,000. The minutiae of exactly how many each army had isn’t as important as recognizing that most historians seem to agree that there’s a difference of about 15,000-20,000 in favor of the Union. Also, it would be a mistake to assume that the Union victory at Gettysburg was mainly due to its outnumbering the Confederate Army of Northern Virginia. If that were the case, the North would have won the war long before April of 1865. So when it comes to the numbers we use in Addressing Gettysburg, they are used more for illustrative purposes than actuarial figures. When our sources are conflicting with each other on these figures, we yield to the numbers used by the National Park Service of each battlefield we discuss, or the American Battlefield Trust. The terms discussed in this upload can be found, along with a multitude of others, on the American Battlefield trust’s website. We extrapolate on many of these definitions.

Gettysburg Glossary


Company: A group of 50 to 100 soldiers led by a captain. 10 companies = 1 regiment. Smaller units within a company are platoons which are made up of squads.


Regiment: The building blocks of the army were regiments. On paper, each regiment, was comprised of ten companies of 100 men. Those companies would be recruited in a town or several nearby towns and sent to their respective state capitals to be trained and mustered into service as part of a regiment. Regiments would be numbered in order of appearance, for the most part, for example, the First Pennsylvania Volunteer infantry, the second Pennsylvania volunteer infantry, etc. This was also done for cavalry units with the word “cavalry” replacing the word “infantry”. So, there would be a first Pennsylvania volunteer infantry and a first Pennsylvania volunteer cavalry. They were men who answered the call for volunteers at the outbreak of the war and fell under the volunteer service. Regiments who were part of the Federal service, or “regular army”, would be numbered as the First United States cavalry or infantry and so on.  As the war pressed on, these numbers diminished so that, by Gettysburg, the average size of a Union regiment was around 350 men and a Confederate regiment being slightly larger. This was not a reflection of the populations in the north and south, but, rather, a reflection of the method of integrating raw recruits into the army. Northern recruits were placed into new regiments while southern recruits were mingled into veteran units. A regiment was officially led by a field officer at the rank of colonel. When a colonel was absent due to sickness, wounding, death or being placed in command of the brigade to which the regiment belonged, lower ranking officers such as lieutenant colonels, majors and even captains moved up to command the regiment. Multiple regiments would be organized into brigades.


Brigade: A brigade was typically three to five, sometimes six, regiments. On paper, its strength should be 3000 to 5000 men. But, by Gettysburg, the average Union brigade might number around 1000 to around 1500 men, while its confederate counterpart might be slightly larger. One noteworthy brigade was the Irish Brigade. At the battle of Fredericksburg in December, 1862, the brigade numbered around 1200 men and sustained about 45% casualties. In the interim months, they would sustain some more at Chancellorsville (though not nearly as many), and would suffer the typical losses from sickness and disease. All of these factors combined to whittle their numbers down to just over 500 men by the time of the battle of Gettysburg in July, 1863.


Division: Once a brigade was formed, it was assigned to a division. In the Union army at Gettysburg, a division typically had between two and four brigades. In the Confederate army at Gettysburg, a division had between 3 and 5 brigades, with Pickett’s Division being an example of one with three brigades, while Rodes’ Division is one example of a division with five brigades. Union divisions were numbered and their respective corps badges would be either red, white or blue, indicating first division, second division or third division, respectively, although commonly, and in this podcast, we will refer to these divisions by the commanders’ names. Confederate divisions were named for their commanders. This could lead to some confusion when the commander for which the division is named is out of action. At Gettysburg, for example, when Pettigrew rose to command Heth’s Division after Heth was wounded on the first day, it was still known as Heth’s Division, but for simplicity’s sake, Addressing Gettysburg will make note of the change in commanders and refer to it as Pettigrew’s Division when discussing its participation in the July 3rd assault on the Union center, popularly known as “Pickett’s Charge”.


Corps: A very large group of soldiers led by a major general in the Union Army or a lieutenant general in the Confederate Army. Union Corps were designated by a Roman numeral while Confederate corps were also numbered, but often called by the name of their commanding general (as in Longstreet’s Corps). Two or more divisions make up a corps. At Gettysburg, the average Union Corps numbered somewhere around 10,000 men, with the Sixth Corps coming in slightly larger with between 14,000 and 16,000, depending on your source. Confederate Corps will be about double the size of its Union counterpart.


Army: The largest organizational group of soldiers, made up of one or more corps. There were 16 Union armies (named after rivers, such as the Army of the Potomac) and 23 Confederate armies (named after states or regions, such as the Army of Northern Virginia). At Gettysburg, only the Union Army of the Potomac and the Confederate Army of Northern Virginia would be present.

Branches of Service

Infantry: That branch of the army in which soldiers traveled by foot. Infantry was the main fighting force of the army. It was called on to take positions or hold positions.


Cavalry: That branch of the army in which soldiers traveled by horse. Cavalry’s role was to gather intelligence, screen the movements of the main body of the army, guard the rear of the army, supplies, prisoners, wagon trains. It might help the listener to think of cavalry as, essentially, scouts. This is because the absence of JEB Stuart’s cavalry will play into many of the decisions Robert E Lee made during the three-day battle.


Artillery: That branch of the army that organized, dispersed and operated cannon, rifled guns and mortars of the field, siege and naval classes. Artillery at Gettysburg was of the field artillery classification.At the start of the war, the U.S. Army had 2,283 guns on hand, but only about 10% of these were field artillery pieces. By the end of the war, the army had 3,325 guns, of which 53% were field pieces. The army reported as “supplied to the army during the war” the following quantities: 7,892 guns, 6,335,295 artillery projectiles, 2,862,177 rounds of fixed artillery ammunition, 45,258 tons of lead metal, and 13,320 tons of gunpowder.

Other Terms Used on Addressing Gettysburg

Aide-de-Camp: A soldier who was appointed by an officer to be his confidential assistant.  The aide wrote and delivered orders and held a position of responsibility which required him to know troop positions and where officer quarters were located.  The aide-de-camp was an officer by virtue of his position and he took orders from his commander only.


Battery: The basic unit of soldiers in an artillery regiment; similar to a company in an infantry regiment. Batteries included 6 cannon (with the horses, ammunition, and equipment needed to move and fire them), 155 men, a captain, 30 other officers, 2 buglers, 52 drivers, and 70 cannoneers. As the War dragged on, very few batteries fought at full strength. A battery can also be the position on a battlefield where cannon are located.


Bivouac:  (pronounced BIH-voo-ack) Temporary soldier encampment in which soldiers were provided no shelter other than what could be assembled quickly, such as branches; sleeping in the open.


Border States: The states of Maryland, Delaware, Kentucky, and Missouri. Although these states did not officially join the Confederacy, many of their citizens supported the South.


Breastworks:  Barriers which were about breast-high and protected soldiers from enemy fire.


Breech-loading: Rifle-muskets that could be loaded at the breech (in the middle between the barrel and the stock) instead of from the end (by shoving gunpowder and a ball down the barrel) were called breech-loading guns


Campaign: A series of military operations that form a distinct phase of the War


Canister: Canister shot was the deadliest type of ammunition, consisting of a thin metal container loaded with layers of lead or iron balls packed in sawdust. Upon exiting the muzzle, the container disintegrated, and the balls fanned out as the equivalent of a shotgun blast. The effective range of canister was only 400 yards (370 m), but within that range dozens of enemy infantrymen could be mowed down. Even more devastating was “double canister”, generally used only in dire circumstances at extremely close range, where two containers of balls were fired simultaneously.


Carbine: A breech-loading, single-shot, rifle-barreled gun primarily used by cavalry troops. A carbine’s barrel is several inches shorter than a regular rifle-musket.


Case: These were antipersonnel projectiles carrying a smaller burst charge than shell, but designed to be more effective against exposed troops. While shell produced only a few large fragments, case was loaded with lead or iron balls and was designed to burst above and before the enemy line, showering down many more small but destructive projectiles on the enemy. The effect was analogous to a weaker version of canister. With case the lethality of the balls and fragments came from the velocity of the projectile itself – the small burst charge only fragmented the case and dispersed the shrapnel. The spherical case used in a 12-pounder Napoleon contained 78 balls. The name shrapnel derives from its inventor, Henry Shrapnel.
The primary limitations to case effectiveness came in judging the range, setting the fuse accordingly, and the reliability and variability of the fuse itself


Caisson: The caisson was also a two-wheeled carriage. It carried two ammunition chests and a spare wheel. A fully loaded limber and caisson combination weighed 3,811 pounds The limbers, caissons, and gun carriages were all constructed of oak. Each ammunition chest typically carried about 500 pounds of ammunition or supplies. In addition to these vehicles, there were also battery supply wagons and portable forges that were used to service the guns.


Charge: To rush towards the enemy. “A charge” can refer to the act of rushing the enemy’s lines by cavalry or infantry, but also the amount of gunpowder loaded into a firearm in order to send the projectile out of the gun’s barrel.


Courier:  A soldier who served the officers of his regiment by carrying messages.


Defeat in Detail:  Defeating a military force unit by unit.  This occurred when units were unable to support one another, often because of distance.


Dysentery: Intestinal disease causing severe diarrhea.  Dysentery was a leading cause of deaths by disease.


Entrenchments: Long cuts (trenches) dug out of the earth with the dirt piled up into a mound in front; used for defense.


Earthwork: A field fortification (such as a trench or a mound) made of earth. Earthworks were used to protect troops during battles or sieges, to protect artillery batteries, and to slow an advancing enemy.


Flank:  Used as a noun, a “flank” is the end (or side) of a military position, also called a “wing”.  An unprotected flank is “in the air”, while a protected flank is a “refused flank”.  Used as a verb, “to flank” is to move around and gain the side of an enemy position, avoiding a frontal assault.


Garrison: A group of soldiers stationed at a military post.


Grapeshot: By the time of Gettysburg, this was relegated to a term used interchangeably with canister. While similar to canister, grapeshot originated in Naval use for firing into an enemy ship at close range in order to cut the rigging and sails and clear the decks of personnel. While grapeshot was used for a period of time in the field, canister had come to replace grapeshot’s use on land in the American Civil war. The period Ordnance and Gunnery work states that grape was excluded from “field and mountain services.


Hardtack: Hardtack is a term used to describe the hard crackers often issued to soldiers of both sides during the Civil War.  These crackers consisted of nothing more than flour, water, and salt. They were simple and inexpensive to make in very large quantities.  However, these crackers became almost rock solid once they went stale.


Haversack:  Small canvas bag, about one foot square, used to carry a soldier’s food.  Typically, these bags were painted with black tar to make them waterproof.


Howitzer:  A cannon which fired hollow projectiles and was generally lighter and shorter than its solid-shot cousins.  A howitzer’s projectiles had a smaller powder charge. Also, canister projectiles contained more small balls than other types of canister.  Howitzers were useful in defending fortifications and causing disorder within a fortification by an attacking force


Interior Lines:  A military strategy which holds that the fastest, most efficient maneuvers, transportation and communication are conducted within an enclosed geographic area as opposed to outside the geographic area.


Kepi:  Cap worn by Civil War soldiers; more prevalent among Union soldiers.


Limber:  A two-wheeled cart that carried one ammunition chest for an artillery piece. The artillery piece could be attached to the limber, which would allow both to be pulled by a team of horses.  Also verb: The practice of attaching a piece of artillery to the limber that holds its ammunition.


Militia: Troops, like the National Guard, who are only called out to defend the land in an emergency.


Muster: To formally enroll in the army or to call roll.


Muzzle-loading: Muzzle-loading muskets or rifle muskets had to be loaded from the end by putting the gunpowder and the bullet or ball down the barrel. The vast majority of small arms and artillery used at Gettysburg were muzzle-loading weapons


Napoleon Gun:  Another name for the Model 1857 gun howitzer.  This lighter, more maneuverable field artillery piece fired 12 pound projectiles and was very popular with both Federal and Confederate armies


Napoleonic Tactics: The tactics used by Napoleon Bonaparte that were studied by military men and cadets at West Point before the Civil War. His tactics were brilliant for the technology of warfare at the time he was fighting. However, by the Civil War, weapons had longer ranges and were more accurate than they had been in Napoleon’s day.


Ordnance:  The term used for military supplies, such as weaponry and ammunition.


Parrott Gun:  A rifled artillery piece with a reinforcing band at the rear, or breech.  Parrott guns were used by both the Army and the Navy, and ranged from 10-pounders to 300-pounders.  They were named after their designer, Robert Parker Parrott.


Picket: Soldiers posted on guard ahead of a main force. Pickets included about 40 or 50 men each. Several pickets would form a rough line in front of the main army’s camp. In case of enemy attack, the pickets usually would have time to warn the rest of the force. During the Gettysburg Campaign, it was a picket line that first encountered Longstreet’s spy names “Harrison” and brought him to Longstreet’s chief of staff, Moxley Sorrel.


Pontoon Bridge:  (pronounced pawn-TOON)  A floating bridge which was constructed by anchoring a series of large, flat-bottomed boats across a waterway and then laying wooden planks across them.  The planks (the “chess”) were anchored by side rails and then covered with a layer of soil to protect it and to dampen sounds. Pontoon bridges were extremely important to the outcome of several battles, including Fredericksburg.


Quartermaster: The officer who was responsible for supplying clothing, supplies and food for the troops.


Reserve(s):  Part(s) of the army which were withheld from fighting during a particular battle but ready and available to fight if necessary


Rifle-Musket: The common weapon of the Civil War infantryman, it was a firearm fired from the shoulder. It differed from a regular musket by the grooves (called rifling) cut into the inside of the barrel. When the exploding powder thrusts the bullet forward, the grooves in the barrel make it spin, just like a football spirals through the air. Rifle-muskets were more accurate and had a longer range than smoothbore weapons.


Shot: A solid, round projectile, shot from a cannon.


Shell: A hollow projectile, shot from a cannon; a shell was filled with powder and lit by a fuse when it was fired. Shells exploded when their fuse burned down to the level of the powder. Depending on the length of the fuse, artillerymen could decide when they wanted the shell to burst.


Skirmish: A minor fight.


Spike:  To make an artillery piece unusable so that it could not be used by the enemy if captured.


Theater: A theater of war is a region or area where fighting takes place.


Traverse:  A mound of earth used to protect gun positions from explosion or to defilade the inside of a field work or fortification.


Vedette(or Vidette):  A mounted sentry stationed in advance of a picket line


Works: Fortified structures designed to strengthen a position in battle. This includes earthworks, fieldworks, entrenchments, siege lines, etc.


Zouave: (pronounced zoo-ahv or zwahv) A zouave regiment was characterized by its soldiers’ bright, colorful uniforms which usually included baggy trousers, a vest, and a fez in different combinations of red, white, and blue. American zouave units were found in both Union and Confederate armies. They were modeled after French African troops who were known for their bravery and marksmanship.