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American Civil War Life: Filling The Ranks – Order of Battle: Brigade and Above

I'm a Sr. Financial Analyst from Long Island, NY and am an American Civil War buff and Living Historian (Company H, 119th NY Volunteers).


Two or more Regiments were consolidated into the next largest unit, which was called a Brigade (Figure 1). The standard number of Regiments per Brigade in the U.S. Army was four, though there are examples of Brigades containing as few as two Regiments and as many as a dozen or more.

Especially in the Union army, there existed the practice of Brigading together Regiments from different states, rarely allowing more than two Regiments from the same state. There were two reasons for this:

  • Concern over Casualties
  • Influence of the State Governors

If a Brigade contained men from only one state, and it was ever particularly hard-hit in terms of casualties, the state from which that Brigade drew its manpower might severely reduce its support for the war. This meant less and less recruits from that state to fill the ranks.

As for the Governors, they essentially created the Militia and Volunteer Regiments. The troops within them, along with the soldiers’ families at home, were their constituents. Governors thus took it upon themselves to look out for the welfare of the Regiments of their states (probably currying soldiers' favor and votes in the process). Governors, hearing of poor conditions within, or faulty senior-level leadership upon, their creations often took steps to interdict and interfere. They often wielded great influence on their Regiments. If several same-state Regiments were brigaded together, a governor would have been able to influence and/or interfere with all of them much more easily. If a governor ever decided to order one or more same-state Brigades back home (even if the governor was really not allowed to do so), the Brigades might very well obey. Army commanders wanted to minimize governor influence so that they could control their forces more effectively and with fewer restrictions. The situation of multiple commanders – commanding general AND state governors in this case - creates confusion, regardless of the time period.

Governor-interference was a very real concern, and it occurred a number of times (sometimes in very beneficial ways, as it turned out). However, Brigades made up of Regiments from different states often did not bond together well. This caused each such organized Brigade to be less than “the sum of its parts”. It caused the men to rally around only their own individual Regiments, rather than with the other Regiments in the same Brigade. Those very few Brigades from one state tended to bond and fight together very well, making them particularly effective. The First and Second Vermont Brigades, the Excelsior (New York) Brigade, and the New Jersey Brigade are excellent examples of same-state Brigades that had superb combat records.

The following list details the Brigade’s commander and his administrative staff:

A Brigadier General – he was the Brigade’s commanding officer, who was appointed by his immediate superior. His rank as a general officer, as with all general officer ranks, needed to be confirmed by the federal government.

One or Two Aides-de-Camp – they wrote out the orders of the commander and sometimes delivered them personally if needed. Each Aide needed to be thoroughly knowledgeable in the troop positions, routes of marches, and locations of the commanding officers in the Brigade. The rank of an Aide could have been as low as Captain or as high as Lieutenant Colonel.

An Adjutant General (or just Adjutant), a Quartermaster officer, Commissary officer, a Surgeon, and a Chaplain – all these positions were as described in the Regiment section, only the duties of these staff members encompassed those of the entire Brigade.

An Ordnance officer – he was in charge of supplying and maintaining the Brigade’s firearms (and cannon, if a battery was attached). This position may have originally been created if the Brigade was on duty independent of any larger parent unit. However, it eventually became a Brigade staff position regardless of the Brigade’s assignment.

An Inspector-General (or just Inspector) – he was responsible for ensuring regulations were followed, training and drilling was conducted, and all supplies and equipment were up to standards and ready for use.

Other staff members may have included an Assistant Adjutant General, one or two Assistant Surgeons, and an Assistant Inspector General. Brigade commanders, and above, sometimes had a certain amount of leeway in organizing their staffs. Not every commander had the same staff, but the above listing is a fair “template”. In addition, there were clerks or couriers (enlisted men and/or NCO’s) to handle other low-level administrative and communications duties as meted out by the staff officers and/or commander.

As for designating the Brigades, some were originally designated sequentially, by number, in the order in which they were organized within the entire region (ie. 14th Brigade). Most other Brigades were designated sequentially, by number, only within their next largest units. By mid-1863, this latter method of Brigade designation was standardized throughout the U.S. Army.

As hinted previously, some Brigades came to be known by nicknames rather than by their official numerical designations. Generally, these were Brigades that distinguished themselves somehow. Comprising all New Jersey Regiments made the nickname “New Jersey” Brigade pretty much inevitable for that unit. An army commander admired one particular Brigade’s prowess in battle, noting that they “stood like iron”, so that unit earned the sobriquet “Iron” Brigade. The “Irish Brigade”, not surprisingly, had a sizeable number of men that originally hailed from Ireland. And The “First Vermont” Brigade earned its nickname both for its Regiments all hailing from Vermont as well as for its reputation in hard marching and extremely stubborn fighting.

Figure 1: A Brigade subdivided into four Regiments.

Figure 1: A Brigade subdivided into four Regiments.

Photo of the Excelsior Brigade drawn up for a review

Photo of the Excelsior Brigade drawn up for a review

Second image of the Excelsior Brigade at review

Second image of the Excelsior Brigade at review


Two or more Brigades were consolidated into a Division (Figure 2).

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There were rare cases of Divisions comprising men from a single state (ie. Pennsylvania Reserve Divisions) but the jumbling of Regiments per Brigade rendered that phenomenon nearly impossible.

The following list details the Division’s commander and his administrative staff:

A Major General – he was the commanding officer of a Division, who was appointed by his immediate superior.

Three Aides-de-Camp

An Adjutant and Assistant Adjutant

Two Commissary officers

A Chief of Ordnance

An Inspector and Assistant Inspector

A Surgeon

A Quartermaster

The duties of these staff members were as earlier stated, only the duties were those for the Division as a whole.

Just like for the Brigades, designating the Divisions varied in the first two years for the same reasons. By mid-1863, Division designations were standardized by the method of sequential order within the next largest unit.

Figure 2: A Division subdivided into two or three Brigades.

Figure 2: A Division subdivided into two or three Brigades.

A Division in a mock battle

A Division in a mock battle

A Division is arrayed to view an execution of one of its members

A Division is arrayed to view an execution of one of its members

Wing / Corps

During the early months of the War, if two or more Divisions were grouped together, the resulting unit was called a Wing.

In the second year of the war, President Lincoln authorized the Corps formations, each comprising two or more Divisions (Figure 3).

The following list details the Wing / Corps’ commander and his administrative staff:

A Senior Major General – he was the commanding officer of the Wing / Corps, who was appointed by his immediate superior or by the President.

The staff of a Wing / Corps commander was very similar to the afore-mentioned Division and Brigade staffs with a few possible additions like these:

  • Chief of Staff
  • Chief Engineering Officer
  • Chief of Artillery
  • Provost Marshal

Chief of Staff – he was the right-hand man of the Wing / Corps commander. He was responsible for drafting the orders and overseeing the necessary logistics, including establishing objective timetables and stockpiling supplies.

Chief Engineering Officer – he was responsible for engineering efforts: road, bridge, and dam building, construction of earthworks, fortresses, and obstructions.

Chief of Artillery – he headed the artillery efforts of the Artillery Brigade attached to the Wing / Corps.

Provost Marshal – he headed the Provost Guard (military police) and was often responsible for the safety of the Wing / Corps commander. He was also responsible for policing the Wing / Corps, incarcerating enemy prisoners, and maintaining order.

A Wing was often designated by its place in the line of battle (ie. Left Wing, Right Wing, Center Wing).

A Corps was designated by a number, and by early 1863, that number was unique throughout the entire branch of the Army. The number was a Roman numeral (ie. VI Corps) or was spelled out (ie. Sixth Corps). And often, army commanders referred to them as Army Corps (ie. II, or Second, Army Corps).

In 1863, corps badges were adopted in the Eastern theatre as a way of helping Corps and Division commanders distinguish officers and men in their commands. This practice grew to involve nearly all Corps by the war’s end. The badge, which was unique for each Corps, was usually worn on the top, or side, of the men’s headgear. This way, officers on horseback could more easily see the badges and ascertain whether or not they were among men they commanded. The shape of the badge denoted the Corps to which the wearer belonged (ie. a Disc denoted I Corps, a Trefoil (three-leaf clover) denoted II Corps, etc). The color of the badge denoted the Division within the Corps:

Red - 1st Division

White - 2nd Division

Blue - 3rd Division

If more than three Divisions were within a Corps, then Green was used for the 4th Division, and Orange was for the 5th Division.

It bears noting that not every Corps adopted a badge by war’s end, but almost all did. All Corps currently have badges now.

Figure 3: A Corps subdivided into two or three Divisions.

Figure 3: A Corps subdivided into two or three Divisions.

The various Corps Badges adopted by the Union Army

The various Corps Badges adopted by the Union Army

Headquarters of 6th Army Corps

Headquarters of 6th Army Corps


Two or more Wings / Corps were consolidated into the next, and most often largest, operating unit, the Army (Figure 4). Before the Wings / Corps were created, two or more Divisions comprised an Army.

The commanding officer of an Army was appointed by the general in chief (the top officer of the U.S. Army) or the President, and was often the most senior general available and qualified.

The staff of the Army commander was very similar to that of a Wing / Corps commander with possible additions of:

  • Chief Topographical Officer
  • Chief Signal Officer
  • Paymaster
  • Chief of Artillery
  • Chief of Military Intelligence

Chief Topographical Officer – he was responsible for map-making and distributing the finished maps to all general officers.

Chief Signal Officer – he was responsible for the army-wide communications technology, including the telegraph, signal flags, signal torches, and the coding of the messages being sent.

Paymaster – he was responsible for the distribution of proper payments to the troops.

Chief of Artillery – he was responsible for the reserve artillery, and the replacement and repairing of damaged artillery batteries throughout the Army.

Chief of Military Intelligence – he was responsible for all information regarding the enemy forces and enemy territory.

Armies were designated by name and often they derived their names from geographical regions (administrative areas, to be explained soon) to which they were assigned and in which they primarily operated (ie. The Army of the Potomac), and they derived their names from the Districts or Departments in which they were assigned and operated. It bears noting that armies often moved out of their assigned areas due to contingencies. However their names did not necessarily change as a result.

Figure 4: An Army subdivided into two or three Corps.

Figure 4: An Army subdivided into two or three Corps.

Headquarters of the Army of the Potomac

Headquarters of the Army of the Potomac

Special Case Units

There were a couple of special military units worthy of mention, temporary or rare as they were:

1) Wing, or Grand Division, and

2) More Than 1 Army under 1 Commander

Wing / Grand Division

Two Corps could have been grouped together within the same Army to form what was called either a Wing (not to be confused with the predecessor to the Corps), or a Grand Division. The commanding officer was appointed by the Army Commander, but was most likely the Corps commander with the greater seniority. He, in turn, appointed the most senior Division commander to command his former Corps, and so on down the chain of command.

As a Grand Division, this new unit had once been created to cut down on the number of Corps Commanders to report to the Army Commander, a perceived streamlining of the chain of command.

An example of the usage of this unit is within the Army of the Potomac in late 1862, during the Fredericksburg Campaign.

Other times, as a Wing, the new unit was created to enable the Army to cover a wide swath of territory and, thus, make easier the attempt to locate the enemy. When the enemy was encountered, two (or more) Corps in that area, under one commander, maintained enough strength to, at least temporarily, fight on its own against the enemy force until the rest of the Army arrived. A great example of this was during the First Day of the Battle of Gettysburg.

Figure 7: A Wing or a Grand Division comprised of two Corps.

Figure 7: A Wing or a Grand Division comprised of two Corps.

More Than One Army Under One Commander

In extremely rare circumstances, two or more Armies fought together under one commanding officer. In today's terms, that resulting unit is called an Army Group, but that designation did not exist during the American Civil War.

This rarity usually occurred when several geographic regions (first mentioned in the Army section) , were merged or grouped together. Why were geographic regions merged or subdivided? There were many reasons, but they were mostly due to the need for greater efficiency of action, the increased, or lack thereof, threat from enemy forces in those geographic regions, or due to political considerations.

Any Armies of those now-merged regions might have merged into one Army.

An example of this was the merger of the Army of Virginia with the Army of the Potomac in the late summer of 1862. The result was the continuation of the Army of the Potomac.

Another example of this was the mid-1864 merger of several regions in Maryland and Virginia. The major military presence in the new combined area, a small force called the Army of West Virginia, was then joined by three Corps from areas outside this new region to form the Army of the Shenandoah. The Army of West Virginia, which had three Divisions, thus became a Corps within the new Army, but it retained its identity and leadership throughout its existence.

Alternately, each Army could have continued as unaltered and separate entities, with the same commanders, but with one overall commander for all of them.

A perfect example of this latter scenario was the merger, in late 1863, of the regions of Ohio, Kentucky, and Tennessee into one large region. Each of these regions included an Army. The three Armies of this new large region each continued in existence and with its own Army commander, and all operated together under one overall commander.

This merger of regions and appointment of overall commanding officers was performed by the general-in-chief, or the Secretary of War, or the President. The commander was generally the most senior or most qualified of the Army Commanders.

Geographic Regions

And now some explanation on the oft-mentioned “geographic regions”.

These geographic regions, as implied by the description, were geographic subdivisions of the United States. They were created by the President and/or the Secretary of War and, in the case of the American Civil War, reflected areas that were under the control of the U.S. military. As more areas fell under control of the U.S. military, new geographic regions were either created or added to existing regions. All the while, existing regions were merged, subdivided, discontinued, resurrected, etc. as was determined by leadership to be necessary at the time.

Each region was designated by a name that was descriptive of the part of the Union it encompassed.

These regions were commanded by Army officers, normally of the General rank. It was necessary, for command and control purposes, for the Commanders to be stationed within the areas of their responsibilities, or at least within steady means of communication and logistics with them.


In the beginning of the War, Departments were the largest and most important geographical regions. Department Commanders reported to the War Department or to a superior Commander (if one existed).

If deemed necessary, for greater operational control or for contingencies, a Department could be subdivided into smaller areas.

In some cases, Departments were one and the same with Armies that operated in the same area. Two examples include:

1) The Department and Army of the Potomac

2) The Army of Virginia, which became its own Department after the merger of the Rappahannock, Shenandoah, and Mountain Departments.

The Army Commander was often also the Department Commander.

As the War continued, Departments were often merged or subdivided due to contingencies or efficiencies, and Department names either changed or disappeared. Therefore, the affected Armies, which often derived their names from those of the Departments in which they operated, could have officially changed names several times during the War. However, it was not unusual for military forces to be referenced by previous, or more popular, names. The Army of the Frontier contained three Divisions, officially called the 1st, 2nd, and 3rd Divisions. However, their prior names – the Kansas Division and the Missouri Divisions, continued to be the preferred monikers of those units. For example, the Department of the Gulf was changed to the Department of West Mississippi, but Army of the Gulf continued to be the preferred moniker of the force that operated in this Department.

Department Commanders were responsible for the protection and maintenance of Federal installations in their areas, for support of field Armies while they operated within their Departmental boundaries, for Departmental logistics, and for recruitment and conscription efforts.

For the latter effort, emergencies (for example, enemy cavalry raids) sometimes called for the raising of many units from the Department’s civilian population for defense purposes and to augment any existing forces within the Department, but those units raised were generally local Militia Companies. Any resulting military force from an emergency would have been temporary.

Military Divisions

From late 1863 on, Military Divisions were created and supplanted Departments as the largest of the geographic regions. Military Divisions were groupings of several (not all) Departments, each with its own Commander, and Department Commanders reported to the Military Division Commanders.

Military Division Commanders had essentially the same responsibilities as those for Department Commanders, but for the entire Military Division in scope.

Military Divisions became necessary due to greater needs for cooperation among Departments and to support larger and more mobile Armies.

Figure 8: A Military Division comprised of three Departments.

Figure 8: A Military Division comprised of three Departments.


As mentioned in the Departments section, Departments could be subdivided.

Subdivisions of Departments were called Districts.

Each District had its own Commander who reported to the Department Commander.

A Department subdivided into two or more Districts

A Department subdivided into two or more Districts


If deemed necessary, a District could be subdivided into smaller areas.

Subdivisions of Districts were called Sub-Districts.

Each Sub-District had its own Commander who reported to the District Commander. Responsibilities were similar.

A District subdivided into two or more Sub-Districts

A District subdivided into two or more Sub-Districts

Additional Reading

A Wikipedia article, Union Army Districts, Departments, and Divisions, offers a remarkable outline of the many and various geographic subdivisions that existed for the Union during the War including dates of creation, operation, and discontinuation. Not all information is readily available, but this outline will give a great example of how fluid was this area of army administration and how difficult is it to create a stable generalization of the hierarchy.

July 30, 1862

The past 22 days have been busy and eventful ones to me. Thursday, July 10th, enlisted as a volunteer in the service of the U.S. Soon after the President’s call for the 300,000 volunteers felt it my duty to be one of them, feel it as much a Christian as a political duty, and feel that every citizen ought to feel it so. And certainly have never felt more peace of mind as flowing from a sense of duty done, as in this matter of enlistment into the service of our country. In most of the towns of our state volunteering goes on rapidly. In others, however, there seems to be but little true patriotism. All towns are offering liberal bounties, varying from one to three hundred dollars. I fear that some of our volunteers go more from motives founded in dollars and cents than from those drawn from true patriotism. May God bless our land and help us as a people to have that true patriotism which is founded in true Christian and political principles. I have been at home all day or nearly so, having left Mr. Boyden’s Monday night. I have been busy packing my effects and preparing my camp equipage. Tomorrow go to camp at Lynnfield. May Thy blessing, My Heavenly father, be with me, and aid me to have thy love and service first and foremost upon the affections of my heart, and be the foundation motives of each thought, word and act, for Christ’s sake.

- Henry W. Tisdale, Company I, Thirty-Fifth Regiment, Massachusetts Volunteer Infantry


For my next series in this realm, I shall now turn my attention to the experiences of those that filled the ranks. My next series of articles is called American Civil War Life: Union Infantryman – Life In Camp.

© 2013 Gary Tameling


CJ Kelly from the PNW on November 03, 2013:

Great stuff once again. Detailed, yet very readable. I'm guilty of very often thinking of Civil War units as volunteer or ad hoc groups (with the exception of the Army of the Potomac). But by the end of the war, the complex nature of the organization resembled that of WWII. Voted up.

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