Editing Union army (section)

==Personnel==
===Regulars vs. volunteers===
[[File:Currier & Ives - The champions of the Union 1861.jpg|thumb|''The champions of the Union'', an 1861 lithograph by [[Currier and Ives]]]]
During the course of the Civil War, the vast majority of soldiers fighting to preserve the Union were in the [[United States Volunteers|volunteer units]].  The pre-war regular army numbered approximately 16,400 soldiers, but by the end while the Union army had grown to over a million soldiers, the number of regular personnel was still approximately 21,699, of whom several were serving with volunteer forces. Only 62,000 commissions and enlistments in total were issued for the regular army during the war as most new personnel preferred volunteer service.<ref>Eicher, p. 46</ref><ref name="Newell76">Newell & Shrader, p. 76</ref>

Since before the Civil War, the American public had a generally negative view of the nation's armed forces, attributable to a [[Jeffersonian democracy|Jeffersonian]] ideal which saw [[standing armies]] as a threat to democracy and instead valorized the "[[citizen soldier]]" as being more in keeping with American ideals of equality and [[rugged individualism]].<ref name="Newell3">Newell & Shrader, p. 1-3</ref>  This attitude remained unchanged during the Civil War, and afterwards many would attribute the Union's victory to the volunteers rather than the leadership and staff work provided by the regular army.<ref name="Newell312">Newell & Shrader, p. 308-312</ref>  In return, officers of the regular army despised the militia and saw them as having dubious value.  Commentators such as [[Emory Upton]] would later argue that the reliance on militia for the nation's defense was responsible for prolonging conflicts and making them more expensive in both money and lives spent.<ref name="Newell3"/><ref name="Newell312" />

Despite these attitudes towards the regulars, they would serve as an important foundation around which the Union army was built.  In the disastrous [[First Battle of Bull Run]], it was the regulars who acted as rearguard during the retreat while the volunteers fled, and when George McClellan was put in charge of what became the Army of the Potomac he used regular officers and non-commissioned officers to train the volunteers.<ref>Newell & Shrader, p. 210</ref>  Training the volunteers, especially in regards to critical administrative and logistical matters, remained an important function of the regulars during the war.<ref name="Newell308">Newell & Shrader, p. 306-308</ref>  This was particularly the case with regular army artillery, as they were more widely dispersed than the infantry and cavalry (making them more visible to the volunteers) and were assigned to specific units to train their volunteer counterparts.<ref name="Newell285">Newell & Shrader, p. 283-285</ref>

In battle, the regulars' performance could impress even the most battle-hardened volunteers.<ref name="Newell218">Newell & Shrader, p. 215-218</ref>   At [[The Wheatfield]] during the [[Battle of Gettysburg]], the regulars' fighting skill and orderly retirement under fire drew the admiration of many observers, including [[Prince Philippe, Count of Paris]].  As one volunteer put it, "For two years the U.S. Regulars taught us how to be soldiers [;] in the Wheatfield at Gettysburg, they taught us how to die like soldiers."<ref>Newell & Shrader, p. 235</ref>  The regulars became the standard by which the Volunteers were measured, and to be described as being as good or better than them was considered the highest compliment.<ref>Newell & Shrader, p. 312</ref>

===Officers===
[[File:Washington, District of Columbia. Officers of 3d Regiment Massachusetts Heavy Artillery.jpg|thumb|Officers of the [[3rd Massachusetts Heavy Artillery Regiment]] defending the national capital of [[Washington, D.C.]], in 1865, the final year of the Civil War]]
[[Commissioned officers]] in the Union army could be divided in several categories: [[general officer]]s, including [[lieutenant general]], which was added on March 2, 1864, [[major general]]s and [[brigadier general]]s; [[field officers]] including [[colonel]]s, [[lieutenant colonel]]s and [[Major (rank)|major]]s; and [[Company-grade officer|company officers]] including [[Captain (military rank)|captains]], [[first lieutenant]]s and [[second lieutenant]]s. There was further differentiation between line officers, who were members of the artillery, cavalry or infantry branches, and staff officers, who were part of the various departments and bureaus of the War Department. All line officers outranked staff officers except in cases pertaining to their staff assignment, in which they received their orders from their respective department chiefs.<ref name="Eicher30">Eicher, p. 30</ref> Regular general officers outranked volunteer general officers of the same grade regardless of their date of commission, a feature which could have become a subject of contention.<ref name="Eicher23">Eicher, p. 34</ref> The use of [[Brevet (military)#American Civil War|brevet ranks]] was also a common feature of the Union army.

Officer appointments depended on the commission grade and whether it was in the regular or volunteer forces. The President reserved the right to issue commission for all regular officers and for general officers in the volunteer forces. Volunteer field and company-grade officers could be commissioned by either the president or their respective governor. Company officers were also unique in that they were usually elected by members of their company.<ref name="Eicher30" /> The political appointment and/or election of volunteer officers was part of a long-standing militia tradition and of a [[Spoils system|political patronage system]] common in the United States. While many of these officers were West Point graduates or had prior military experience, others had none, nor was military leadership a primary consideration in such appointments.<ref name="Perryville">Staff Ride Handbook for the Battle of Perryville, 8 October 1862. (2005). Fort Leavenworth, KS: Combat Studies Institute, US Army Command and General Staff College. p. 3–6</ref> Such a policy inevitably resulted in the promotion of inept officers over more able commanders. As the war dragged on and casualties mounted, governors reacted to their constituents' complaints and instead began to issue commissions on the basis of battlefield rather than political competence.<ref>Fisher, E. F. (2001). ''Guardians of the Republic: A History of the Noncommissioned Officer Corps of the U.S. Army''. United Kingdom: Stackpole Books. p. 111</ref>

Officers tended to suffer a higher percentage of battle wounds on account of either the necessity of leading their units into combat and their conspicuousness when accompanied by staff and escorts.<ref name="Eicher61" />

Among memorable field leaders of the army were [[Nathaniel Lyon]] (first Union general to be killed in battle during the war), [[William Rosecrans]], [[George Henry Thomas]], [[William Tecumseh Sherman]], [[Phil Sheridan]], and [[Benjamin Butler (politician)|Benjamin F. Butler]].

;Officer ranks
{| style="border:1px solid #8888aa; background-color:#f7f8ff; padding:5px; font-size:95%; margin: 0px 12px 12px 0px;"
{{Ranks and Insignia of Non NATO Armed Forces/OF/Blank}}
|- style="text-align:center;"
| rowspan=2| '''1861–1864'''<ref>{{cite book |author=Adjutant General's Office |title=Regulations for the Uniform and Dress of the Army of the United States 1861 |date=13 March 1861 |publisher=George W. Bowman, Public Printer |location=Washington |url=http://www.usregulars.com/genorder6.html |access-date=9 December 2022 |archive-url=https://web.archive.org/web/20080215222851/http://www.usregulars.com/genorder6.html |archive-date=15 February 2008 |pages=12–13}}</ref>
| colspan=4 rowspan=2| 
| colspan=2| [[File:US Army O9 (1861).svg|100px]]
| colspan=2| [[File:US Army O8 (1861).svg|100px]]
| colspan=2| [[File:US Army O7 (1861).svg|100px]]
| colspan=2| [[File:US Army O6 (1861).svg|100px]]
| colspan=2| [[File:US Army O5 (1861).svg|100px]]
| colspan=2| [[File:US Army O4 (1861).svg|100px]]
| colspan=2| [[File:US Army O3 (1861).svg|100px]]
| colspan=3| [[File:US Army O2 (1861).svg|100px]]
| colspan=3| [[File:US Army O1 (1861).svg|100px]]
|- style="text-align:center;"
| colspan=2| [[Major general (United States)|Major general]]<br>[[Commanding General of the United States Army#Commanding General of the United States Army|Commanding the Army]]
| colspan=2| [[Major general (United States)|Major general]]
| colspan=2| [[Brigadier general (United States)|Brigadier general]]
| colspan=2| [[Colonel (United States)|Colonel]]
| colspan=2| [[Lieutenant Colonel (United States)|Lieutenant colonel]]
| colspan=2| [[Major (United States)|Major]]
| colspan=2| [[Captain (Union Army)|Captain]]
| colspan=3| [[First lieutenant#United States|First lieutenant]]
| colspan=3| [[Second lieutenant#United States|Second lieutenant]]
|- style="text-align:center;"
| rowspan=2| '''1864–1866'''<ref>{{cite web |last1=Searles |first1=Harry |title=General Orders, No. 87 (U.S. War Department) |url=https://www.americanhistorycentral.com/entries/general-orders-no-87-u-s-war-department/#:~:text=On%20March%203%2C%201864%2C%20the%20U.S.%20War%20Department,on%20the%20same%20day%20the%20order%20was%20issued. |website=americanhistorycentral.com |access-date=26 December 2022}}</ref>
| colspan=4 rowspan=2| 
| colspan=2| [[File:US Army O9 (1861).svg|100px]]
| colspan=2| [[File:US Army O8 (1861).svg|100px]]
| colspan=2| [[File:US Army O7 (1861).svg|100px]]
| colspan=2| [[File:US Army O6 (1861).svg|100px]]
| colspan=2| [[File:US Army O5 (1861).svg|100px]]
| colspan=2| [[File:US Army O4 (1861).svg|100px]]
| colspan=2| [[File:US Army O3 (1861).svg|100px]]
| colspan=3| [[File:US Army O2 (1861).svg|100px]]
| colspan=3| [[File:US Army O1 (1861).svg|100px]]
|- style="text-align:center;"
| colspan=2| [[Lieutenant general (United States)|Lieutenant general]]
| colspan=2| [[Major general (United States)|Major general]]
| colspan=2| [[Brigadier general (United States)|Brigadier general]]
| colspan=2| [[Colonel (United States)|Colonel]]
| colspan=2| [[Lieutenant Colonel (United States)|Lieutenant colonel]]
| colspan=2| [[Major (United States)|Major]]
| colspan=2| [[Captain (Union Army)|Captain]]
| colspan=3| [[First lieutenant#United States|First lieutenant]]
| colspan=3| [[Second lieutenant#United States|Second lieutenant]]
|}
*[[Lieutenant general (United States)|Lieutenant general]]: The rank of lieutenant general did not exist in the Union army for most of the war until February 1864, when an [[Act of Congress]] allowed for its creation. A single lieutenant general was authorized to serve as the commander of all the field armies and geographic departments of the United States, under the direction and at the pleasure of the [[President of the United States|President]]. By law, they were allowed two secretaries and four [[aide-de-camp|aides-de-camp]] with the rank of lieutenant colonel, and a [[Chief of staff#In the United States 2|chief of staff]] with the rank of brigadier general.<ref>Kautz, A. V. (1866). Customs of Service for Officers of the Army: As Derived from Law and Regulations and Practiced in the United States Army. United States: J.B. Lippincott & Company. p. 378–380</ref>
*[[Major general (United States)|Major general]]: Major generals were nominally the commanding officer of a division, although given the lack of higher grades of general officers they were also given command of army corps, field armies and geographic departments. In the event two or more officers of the same grade were present in the same army or department, command was decided by seniority. In an exception to this practice, the president was authorized by law to appoint a junior officer to command over his seniors. A major general was allowed a personal staff of three aides-de-camp. These were personally chosen by the general from among the captains and lieutenants of the army and would accompany him whenever his command changed, being separate from the general staff of the unit he commanded.<ref>Kautz (1866), p. 376–377</ref>
*[[Brigadier general (United States)|Brigadier general]]: A brigadier general was typically in command of a brigade, but like major generals it was not uncommon for them to command larger units. They were responsible for the organization and administration of their command, particularly when operating independently. As with major generals they were also allowed a personal staff of two aides-de-camp of lieutenant grade.<ref>Kautz (1866), p. 375–376</ref>
*[[Colonel (United States)|Colonel]]: A colonel was the commanding officer of a regiment, though they might also be assigned the commanding officer of larger units or expeditions.<ref>Kautz (1866), p. 276–277</ref> They oversaw the recruitment, organization and training of their regiment; conducted parades, reviews and inspections; and managed the administration of the unit, ensuring that soldiers were clothed, fed, armed and paid.<ref>Kautz (1866), p. 278–314</ref>
*[[Lieutenant colonel (United States)|Lieutenant colonel]]: A lieutenant colonel was the senior assistant to their regiment's colonel in carrying out his duties and taking command in his absence. When the regiment was split among several posts, the lieutenant colonel would command a [[Detachment (military)|detachment]] of four companies. Of those duties specific to a lieutenant colonel were taking care of the personal property of deceased officers; act as [[officer of the day]] for a brigade; and conduct regimental [[court martial|courts martial]].<ref>Kautz (1866), p. 275–276</ref>
*[[Major (United States)|Major]]: A major acted as an assistant to their regiment's colonel in carrying out his duties and commanded [[Detachment (military)|detachments]] of two or more companies. The specific duties of a major were also the same as a lieutenant colonel.<ref>Kautz (1866), 265–275</ref>
*[[Captain (United States O-3)|Captain]]: A captain was the commanding officer of a company and saw to its administration. This included selecting (with the colonel's approval) and training non-commissioned officers, issuing punishments and conducting courts martial, and maintaining company [[recordkeeping|records and books]] such as inventories and the [[muster roll]].<ref>Kautz (1866), p. 223–260</ref> They also served as the officer of the day at a regimental camp or small post.<ref>Kautz (1866), p. 260</ref>
*[[Lieutenant#Lieutenant|Lieutenant]]: In the US Army there were three grades of lieutenant – [[First lieutenant#United States|first]], [[Second lieutenant#United States|second]] and brevet second. The last grade, limited to one per company, was given to West Point graduates and others worthy of the promotion but for whom there was no vacancy. Regardless of grade, lieutenants acted as assistants to the captain, and in his absence the senior-most lieutenant took command.<ref>Kautz (1866), p. 17–21</ref> Among their various duties they might be assigned to take the daily roll-call, conduct inspections of the troops, and assist with recordkeeping;<ref>Kautz (1866), p. 22–26</ref> oversee the posting of guards when in camp or [[Picket (military)|pickets]] in the field, command [[patrolling|patrols]] or [[Bodyguard|escorts]] for general officers;<ref>Kautz (1866), p. 27–68</ref> and command [[Fatigue duty|fatigue parties]].<ref>Kautz (1866), p. 73–77</ref> Lieutenants were also chosen to serve on their regiment's staff,<ref>Kautz (1866), p. 171</ref> and may be assigned in an acting capacity to serve on the general staff of a higher unit.<ref>Kautz (1866), p. 188</ref>

===Enlisted personnel===
[[File:UnionOfficers.jpg|thumb|Non-commissioned officers of the [[93rd New York Infantry Regiment]] in [[Bealeton, Virginia]], in August 1863]]
[[Non-commissioned officers]] (NCOs) were important in the Union army in maintaining the order and alignment of formations during marches, battles, and transitioning between the two. [[Sergeants]] in particular were vital in this role as general guides and their selection ideally reserved for the most distinguished soldiers. NCOs were also charged with training individuals in how to be soldiers. While the captain or other company-level officers were responsible for training the soldiers when assembled into squads, platoons or as a company, experienced NCOs could take over this training as well.<ref name=Fisher119>Fisher (2001), pages 115–119</ref> NCOs were also responsible for the [[regimental colors]], which helped the unit maintain formation and serve as a rally point for the regiment. Typically a sergeant was designated the [[standard-bearer]] and protected by a [[color guard]] of [[corporal]]s who only opened fire in defense of the colors.<ref>Fisher (2001), pages 121–122</ref> There were a number of staff NCO positions including [[quartermaster sergeant]], [[ordnance sergeant]], and commissary sergeant.

NCOs in the volunteer forces were quite different from their regular counterparts as the war began. Appointed to their role as each regiment was created, they were often on a first-name basis with both their superior officers and the enlisted men they were tasked to lead. Discipline among friends and neighbors was not enforced as strictly as in the regular army, and while some NCOs brought with them prior battlefield experience (whether from the [[Mexican–American War]] or foreign military service) many at the start of the war were as equally ignorant as their officers in military matters.<ref name=Fisher119/><ref name=Fisher114>Fisher (2001), 109–114</ref> Training for these NCOs took place during off-duty hours and often involved lessons based on manuals such as [[William J. Hardee|''Hardee's Tactics'']]. One notable exception was [[Michigan in the American Civil War|Michigan]], which designated [[Fort Wayne (Detroit)|Fort Wayne]] as a training center for both officers and NCOs. As the war progressed NCOs gained valuable experience and even drastic disciplinary measures such as [[execution by firing squad]] were carried out when deemed necessary. The promotion of soldiers to NCOs (and NCOs to officers) was also increasingly based on battlefield performance, although each state maintained their own standards for when and where promotions could be granted.<ref name=Fisher119 /><ref name=Fisher114 />

;Enlisted ranks
{| border="1" cellpadding="2" cellspacing="0" style="margin:auto; width:100%;"
|-
! colspan=11| '''Enlisted Rank Structure'''
|-
! [[Sergeant Major#United States|Sergeant Major]]
! [[Quartermaster Sergeant#United States|Quartermaster Sergeant]]
! [[Ordnance Sergeant]]
! [[First Sergeant#United States|First Sergeant]]
! [[Sergeant#United States|Sergeant]]
! [[Corporal#United States|Corporal]]
! [[Musician (rank)|Musician]]
! [[Private E-2|Private]]
|-
! [[File:Union Army Infantry Sergeant Major.svg|80px]]
! [[File:Union Army Infantry Quartermaster Sergeant.svg|80px]]
! [[File:Union Army Infantry Ordnance Sergeant.svg|80px]]
! [[File:Union Army Infantry First Sergeant.svg|80px]]
! [[File:Union Army Infantry Sergeant.svg|80px]]
! [[File:Union Army Infantry Corporal.svg|80px]]
! No insignia
! No insignia
|}

*[[Sergeant major (United States)|Sergeant Major]]: The sergeant major was the senior-most enlisted soldier of a regiment and was expected to serve as a model for the other enlisted personnel. Appointed by the regiment's colonel, among his responsibilities was to issue orders to the first sergeants, maintain a roster of the sergeants and corporals detailed to various tasks, and assist the regimental adjutant in his duties. If a regiment didn't have a drum major or chief musician, he also had responsibility for overseeing the musicians.<ref>Kautz, A. V. (1864). Customs of Service for Non-commissioned Officers and Soldiers, as Derived from Law and Regulations, and Practised in the Army of the United States: Being a Handbook for the Rank and File of the Army, Showing what are the Rights and Duties, how to Obtain the Former and Perform the Latter, and Thereby Enabling Them to Seek Promotion and Distinction in the Service of Their Country. United States: J.B. Lippincott & Company. p. 172–174</ref>
*[[Quartermaster sergeant#American Civil War|Quartermaster Sergeant]]: The quartermaster sergeant was appointed by the regimental quartermaster to assist him in carrying out his duties. This included maintaining the store of supplies and serving as foreman for various work parties. Separately, each Union cavalry company was also authorized a quartermaster sergeant who performed similar tasks but was answerable to the company commander and first sergeant.<ref>Kautz (1864), p. 165–172</ref>
*Commissary Sergeant: Appointed by the regimental commissary, the commissary sergeant was responsible for assisting him in requisitioning and issuing rations to the regiment. Union cavalry companies and some artillery companies were also authorized a commissary sergeant to perform similar tasks.<ref>Kautz (1864), p. 152–164</ref>
*[[Hospital Steward]]: Regimental hospital stewards were responsible for the care of sick and wounded soldiers and their transportation to a general hospital, along with overseeing of any hospital property and medicines. Appointed by the colonel on the advice of the regiment's senior surgeon, they could direct any musicians (and later any [[U.S. Ambulance Corps|Ambulance Corps]] assets) to assist in carrying out these duties.<ref>Kautz (1864), p. 149–152</ref> Hospital stewards assigned to general hospitals acted as supervisors to the rest of the hospital staff (except for the doctors). A single steward was considered sufficient for a 150-bed hospital, while a 500-bed hospital would require three stewards: a chief steward charged with administration, one to act as pharmacist and a third overseeing the preparation of meals.<ref>Schroeder-Lein, G. R. (2015). ''The Encyclopedia of Civil War Medicine''. United Kingdom: Taylor & Francis. p. 281</ref>
*[[First Sergeant (United States)|First Sergeant]]: The first sergeant was the senior NCO of a company and appointed by the captain to serve as its immediate supervisor. Among his duties were taking roll call, arresting and confining soldiers for offenses committed, and overseeing the company stores (assisted by the company commissary and/or quartermaster sergeants if present).<ref>Kautz (1864), p. 131–149</ref>
*[[Sergeant (United States)|Sergeant]]: Sergeants were chosen from among a company's corporals and important for supervising the other soldiers. Each sergeant was in command of a squad of soldiers and directed them in carrying out their duties while in camp or garrison. In battle, sergeants kept the soldiers in ranks and prevented them from falling out; if necessary this included shooting them if they attempted to run away.<ref>Kautz (1864), p. 116–118</ref> Sergeants oversaw the changing of guards and pickets, confinement of prisoners (which, if numerous enough, would require one sergeant assigned as provost-sergeant), and led patrols and fatigue parties.<ref>Kautz (1864), p. 118–124</ref> One sergeant in the regiment would be chosen as the [[color sergeant]] and, protected by the [[color guard]], carried the [[regimental colors]] on parade and in battle.<ref name=Kautz64p130>Kautz (1864), p. 130–131</ref> 
:Sergeants in the artillery branch commanded individual cannons as the Chief of Piece and were responsible for keeping it maintained and directing its use in battle.<ref>Kautz (1864), pages 124–125</ref> Sergeants of the Ordnance Department (distinct from the separate rank of [[Ordnance Sergeant]]) were employed at the various arsenals and armories with manufacturing and caring for the various arms and equipment. They were referred to as master armorers, master carriage-makers or master blacksmiths early in the war.<ref name=Kautz64p65>Kautz (1864), pages 64–65</ref> Sergeants of the Corps of Engineers, in addition to the normal duties of a sergeant, also had to be knowledgeable in the construction of bridges, forts and other military engineering projects.<ref name=Kautzp66>Kautz (1864), page 66</ref> In the Signal Corps, a sergeant was assigned to each signal officer, from whom he took instruction in order to assist with the sending and receiving of signals and performing mounted reconnaissance.<ref name=Kautz64p67>Kautz (1864), pages 67–68</ref>
*[[Corporal (United States)|Corporal]]: The lowest grade of NCO, corporals would be chosen from among a company's most competent privates and given charge of various tasks and duties. They might be given charge of small parties carrying out fatigue, police or guard duties, and in the absence of the sergeant they may take on their duties.<ref name=Kautz64p102>Kautz (1864), pages 102–111</ref> The five most distinguished corporals of a regiment would be chosen to act as the color guard and accompany the color sergeant.<ref name=Kautz64p130/>
:Artillery corporals acted as gunners and would assist the Chief of Piece in maintaining and aiming the cannon.<ref name=Kautz64p102/> As with sergeants, corporals of the Ordnance Department were employed at its various facilities. Their formal titles were armorer, carriage-maker or blacksmith until revised later in the war.<ref name=Kautz64p65/> Likewise, corporals in the Corps of Engineers were also required to be knowledgeable in practical military engineering in addition to their soldierly skills.<ref name=Kautzp66/>
*[[Private (United States)|Private]]: Privates carried out the basic functions of being a soldier in the Union army. When in camp or garrison they filled in on the various work details and fatigue parties, stood guard and policed the local area. They might be assigned to extra duties such as the company cook, tailor, clerk or as orderlies.<ref>Kautz (1864), pages 22–44</ref> In the field they were employed in tasks commiserate with their roles as infantry, cavalry or artillery soldiers. This included being deployed as pickets, skirmishers or flankers.<ref>Kautz (1864), pages 44–60</ref> 
:Soldiers could also be employed in special duties that were not strictly military in nature: mechanics and laborers, hospital attendants and cooks, regimental armorers, officers' servants, [[Pioneer (military)|pioneers]], [[courier]]s, [[reconnaissance|scouts]] and [[espionage|spies]].<ref>Kautz (1864), pages 91–96</ref> In the Corps of Engineers, Ordnance Department, and Signal Corps, privates were further differentiated as first class or second class. First class Engineer and Ordnance privates were formerly referred to as [[Armed-forces artificer|artificers]], while second class privates were formerly referred to as laborers.<ref name=Kautz64p65/><ref name=Kautz64p67/><ref>Kautz (1864), page 287</ref>

===Southern Unionists===
Southerners who were against the Confederate cause during the Civil War were known as [[Southern Unionists]]. They were also known as Union Loyalists or Lincoln's Loyalists. Within the eleven Confederate states, states such as [[Tennessee]] (especially [[East Tennessee]]), [[Virginia]] (which included [[West Virginia]] at the time), and [[North Carolina]] were home to the largest populations of Unionists. Many areas of [[Appalachia|Southern Appalachia]] harbored pro-Union sentiment as well. As many as 100,000 men living in states under Confederate control would serve in the Union army or pro-Union guerilla groups. Although Southern Unionists came from all classes, most differed socially, culturally, and economically from the region's dominant pre-war [[planter class]].<ref>Scott, E. Carele. [https://warfarehistorynetwork.com/2018/12/21/southerner-vs-southerner-union-supporters-below-the-mason-dixon-line/ Southerner vs. Southerner: Union Supporters Below the Mason-Dixon Line]. ''Warfare History Network''. Retrieved August 1, 2022.</ref>

===Ethnic composition===
[[File:Us colored volunteer infantry.jpg|thumb|The 26th U.S. Colored Volunteer Infantry of the [[United States Colored Troops|U.S. Colored Troops]] at [[Camp William Penn]] in present-day [[Cheltenham Township, Montgomery County, Pennsylvania|Cheltenham Township, Pennsylvania]], in 1865]]
[[File:John Haag, Co. B, 26th Wis. Volunteer Infantry.jpg|thumb|John Haag, a 21-year-old immigrant from [[Germany]], affiliated with Company B of the [[26th Wisconsin Infantry Regiment]] in August 1862<ref>''Chippewa County, Wisconsin Past and Present'', Volume II.  Chicago:  S.J. Clarke Publishing Company, 1913.  p. 258.</ref>]]
Native-born White Americans made up roughly two-thirds of the soldiers in the Union army, with the rest of many different ethnic groups, including large numbers of immigrants. About 25% of the white men who served in the Union army were foreign-born.<ref name="McPherson, pp.36–37"/> The U.S. experienced its heaviest rate of immigration during the 1850s, and the vast majority of these people moved to the [[Northeastern United States|Northeastern]] states. 

Among these immigrants, [[German Americans in the American Civil War|Germans]] constituted the largest group with a million arrivals between 1850 and 1860, many of them [[Forty-Eighters]]. Nearly as many [[Irish Americans in the American Civil War|Irish]] immigrants arrived during the same period.<ref>Germans in the Civil War: The Letters They Wrote Home. (2009). United States: University of North Carolina Press. p. 2</ref> Immigrant soldiers were among the most enthusiastic in the Union army, not only from a desire to help save their adoptive home but to prove their patriotism towards it.<ref name=Axelrod73>Axelrod, A. (2017). Armies South, Armies North. United States: Lyons Press. p. 72-73</ref>  To help cement immigrant enthusiasm and loyalty to the Union, several generals were appointed from these communities, including [[Franz Sigel]] and [[Michael Corcoran]].<ref>Axelrod, A. (2017), p. 86-87</ref>

{| class=wikitable style="text-align:right;"
|+Ethnic composition of Union enlistments<ref>{{cite web|url=https://emergingcivilwar.com/2016/04/08/the-cosmopolitanism-of-the-union-army-what-did-it-mean/|title=The Cosmopolitanism of the Union Army: What Did It Mean?|first=Matt|last=Stanley|website=Emerging Civil War|date=8 April 2016|access-date=9 December 2022}}</ref> 
!Estimates
!Origin
|-
|1,400,000 || align=left |Native-born [[White American]]
|-
|216,000 || align=left |[[Germans]]/[[German-American]]<ref>{{cite book|url=https://books.google.com/books?id=aGgrKlWxpu8C&pg=PA15|title=The Blessed Peace of Freedom: Europeans in Civil War America|first=Dean. B|last=Mahin|page= 15|date=2002|publisher=Potomac Books |isbn=9781574884845 }}</ref>
|-
|210,000 || align=left |[[African American]]
|-
|150,000 || align=left |[[Irish-American|Irish]]-born<ref>{{cite book|url=https://books.google.com/books?id=aGgrKlWxpu8C&pg=PA21|title=The Blessed Peace of Freedom: Europeans in Civil War America|first=Dean. B|last=Mahin|page= 21|date=2002|publisher=Potomac Books |isbn=9781574884845 }}</ref><ref>{{cite book|url=https://books.google.com/books?id=oCYVCgAAQBAJ&pg=PA100|title=Civil War Citizens: Race, Ethnicity, and Identity in America's Bloodiest Conflict|first = Susannah J.|last=Ural|page= 100|year= 2010|publisher=NYU Press |isbn=9780814785706 }}</ref>
|-
|18,000 – 50,000 || align=left |[[Canadian Americans|Canadian]]{{efn|Alternative estimates place the number of enlistees much lower.<ref name=Reid>Reid, R. M. (2014). African Canadians in Union Blue: Volunteering for the Cause in the Civil War. Canada: UBC Press. p. 229</ref><ref name=Winks>Winks, R. W. (1998). Civil War Years: Canada and the United States. Ukraine: McGill-Queen's University Press. p. 179-185</ref>}}
|-
|50,000 || align=left |[[English Americans|English]]-born
|-
|49,000 || align=left |Other ([[Scandinavian American|Scandinavian]], [[Italian American|Italian]], [[Jewish American|Jewish]], [[Mexican American|Mexican]], [[Polish American|Polish]], [[Native Americans in the United States|Native American]])
|-
|40,000 || align=left |[[French Americans|French]]/[[French-Canadian Americans|French-Canadian]]
|-
|colspan="2"|{{Notelist}} 
|}

Many immigrant soldiers formed their own regiments, such as the [[Irish Brigade (United States)|Irish Brigade]], including the [[69th Infantry Regiment (New York)|69th New York]], 63rd New York, 88th New York, 28th Massachusetts, 116th Pennsylvania; the Swiss Rifles (15th Missouri); the [[55th New York Volunteer Infantry|Gardes de Lafayette]] (55th New York); the Garibaldi Guard (39th New York); the Martinez Militia (1st New Mexico); the Polish Legion (58th New York); the [[German Rangers]]; Sigel Rifles (52nd New York, inheriting the 7th); the Cameron Highlanders ([[79th New York Volunteer Infantry]]); and the Scandinavian Regiment (15th Wisconsin).<ref name=Axelrod73/> But for the most part, the foreign-born soldiers were scattered as individuals throughout units.<ref>[http://52ndnysv.com/ The 52nd New York State Volunteers]</ref>

The Confederate army was less diverse: 91% of its soldiers were native-born white men and only 9% were foreign-born white men, with Irish being the largest group, other groups included Germans, French, British, and Mexicans. Most Mexicans happened to have been born when the [[Southwestern United States|Southwest]] was still part of [[Mexico]]. Some Confederate propaganda condemned foreign-born soldiers in the Union army, likening them to the German [[Hessian (soldiers)|Hessian]] troops who fought alongside the [[British Army during the American Revolutionary War]]. A relatively smaller number of [[Native Americans in the United States|Native Americans]], including members of [[Cherokee]], [[Chickasaw]], [[Choctaw]] and [[Muscogee]] peoples, fought for the Confederacy.

====Italian Americans in the Union army====
{{Main|Italian Americans in the Civil War}}
The great majority of [[Italian Americans]], for both demographic and ideological reasons, served in the Union army (including generals [[Edward Ferrero]] and [[Francis B. Spinola]]). Six Italian Americans received the [[Medal of Honor]] during the war, among whom was Colonel [[Luigi Palma di Cesnola]], who later became the first Director of the [[Metropolitan Museum of Arts]] in New York (1879–1904). Most of the Italian-Americans who joined the Union army were recruited from [[New York City]]. Many Italians of note were interested in the war and joined the army, reaching positions of authority. Brigadier General [[Edward Ferrero]] was the original commander of the [[51st New York Volunteer Infantry|51st New York Regiment]].<ref>Belfiglio, p. 169</ref> He commanded both brigades and divisions in the [[Eastern Theater of the American Civil War|eastern]] and [[Western Theater of the American Civil War|western]] theaters of war and later commanded a division of the [[United States Colored Troops]]. Colonel Enrico Fardella, of the same and later of the [[85th New York Volunteer Infantry|85th New York]] regiment, was made a [[Brevet (military)|brevet]] brigadier general when the war ended. [[Francis B. Spinola]] recruited four [[regiment]]s in New York, was soon appointed Brigadier General by President [[Abraham Lincoln]] and given command of the [[Spinola Brigade]]. Later he commanded another unit, the famed [[Excelsior Brigade]].
[[File:March past of the 'Garibaldi Guard' before President Lincoln, 1861-1865 (c1880).jpg|thumb|Review of the [[Garibaldi Guard]] by President [[Abraham Lincoln]]]]

The [[Garibaldi Guard]] recruited volunteers for the Union army from Italy and other European countries to form the [[39th New York Volunteer Infantry Regiment|39th New York Infantry]].<ref>''Images: A Pictorial History of Italian Americans''. New York, 1986, p.26</ref> At the outbreak of the American Civil War, [[Giuseppe Garibaldi]] was a very popular figure. The [[39th New York Volunteer Infantry Regiment]], of whose 350 members were Italian, was nicknamed ''Garibaldi Guard'' in his honor. The unit wore red shirts and ''[[Bersaglieri|bersaglieri plumes]].'' They carried with them both a Union Flag as well as an [[Italian flag]] with the words ''Dio e popolo,'' meaning "God and people."<ref>{{cite journal |last1=Belfiglio |first1=Valentino J. |title=Italians and the American Civil War |journal=Italian Americana |date=Spring–Summer 1978 |volume=4 |issue=2 |page=164 |jstor=41330626 |url=https://www.jstor.org/stable/41330626 |access-date=21 December 2022}}</ref> In 1861 Garibaldi himself volunteered his services to President [[Abraham Lincoln]]. Garibaldi was offered a major general's commission in the U.S. Army through the letter from Secretary of State [[William H. Seward]] to [[Henry Sanford|H. S. Sanford]], the U.S. Minister at [[Brussels]], July 17, 1861.<ref>Mack Smith, Denis, Garibaldi, Prentice-Hall, 1969, pp. 69&ndash;70</ref>

Colonel [[Luigi Palma di Cesnola]], a former Italian and British soldier and veteran of the [[Crimean War]], commanded the 4th New York Cavalry and would rise to become one of the highest ranking Italian officer in the Union army.<ref>Belfiglio, p. 167</ref> He established a military school in New York City where many young Italians were trained and later served in the Union army. Di Cesnola received the [[Medal of Honor]] for his actions during the [[Battle of Aldie]].<ref>{{cite web |title=LOUIS PALMA DI CESNOLA |url=https://www.cmohs.org/recipients/louis-p-di-cesnola |publisher=Congressional Medal of Honor Society |access-date=21 December 2022}}</ref> Two more famous examples were Francesco Casale and Luigi Tinelli, who were instrumental in the formation of the [[39th New York Volunteer Infantry Regiment|39th New York Infantry Regiment]]. According to one evaluation of the [[Official Records of the Union and Confederate Armies]], there were over 200 Italians who served as officers in the U.S. army.<ref>Belfiglio, p. 167</ref>

====African Americans in the Union army====
{{Main|Military history of African Americans in the American Civil War|United States Colored Troops}}
[[File:Unidentified African American Union soldier with a rifle and revolver in front of painted backdrop showing weapons and American flag at Benton Barracks, Saint Louis, Missouri LOC 5229147154 (cropped).jpg|thumb|Portrait of an African American Union soldier at [[Benton Barracks]]]]
By 1860, the [[African American]] or Black population of the United States consisted of four million [[Slavery in the United States|enslaved]] and half a million [[Free Negro|free Blacks]].  When the Civil War began, many freedmen in the North attempted to enlist in federal service but were barred from doing so. Popularly-held prejudices doubted whether Black people could be effective soldiers, and President Lincoln believed allowing their enlistment would anger Northern whites and alienate not just the South but the [[Border states (American Civil War)|Border States]] too.  However he eventually changed his mind and persuaded Congress to authorize the first official Black enlistment system in late 1862, which evolved into the [[United States Colored Troops]].<ref name=USCT>American Civil War: The Definitive Encyclopedia and Document Collection [6 Volumes]: The Definitive Encyclopedia and Document Collection. (2013). United States: ABC-CLIO. p. 10-12, 14–15</ref>

Before they were allowed to enlist, many Black people volunteered their services to the Union army as cooks, nurses, and in other informal roles, and several volunteer regiments of Black troops were raised by the states. These included the [[1st Kansas Colored Infantry Regiment]], the first Black regiment to be raised and the first to engage in combat; the [[1st Louisiana Native Guard (Union)|1st Louisiana Native Guard]], raised from both freedmen and escaped slaves after the [[Capture of New Orleans]]; and the [[54th Massachusetts Infantry Regiment]], which became the most famous Black unit after their valiant participation in the [[Battle of Fort Wagner, Morris Island|Battle of Fort Wagner]].  Their efforts helped to dispel the notion that Black soldiers were a liability, allowing about 200,000 Black soldiers to serve in the Union army during the Civil War.<ref name=USCT/>

Even as they served their country, Black soldiers were subject to discrimination. They were more often assigned to menial labor. Some Union officers refused to employ them in combat, but when they were they often had to use inferior weapons and equipment.  Black soldiers were paid less than white soldiers ($10 vs $16 per month) until Congress yielded to public pressure and approved equal pay in June 1864. Black units were led predominantly by white officers, and while more than a hundred Black men were eventually made officers (not counting those [[Passing (racial identity)|passing]] as white), none were promoted to a rank higher than major.  If captured by Confederate forces, Black soldiers risked being made slaves or [[summarily executed]].<ref name=USCT/>

===Women in the Union army===
[[File:Kady Brownell CDV.jpg|thumb|[[Kady Brownell]], a [[vivandière]] from [[Rhode Island in the American Civil War|Rhode Island]]]]
Women took on many significant roles in the Union army and were important to its ultimate success on the battlefield.  The most direct way they could help was to enlist and fight as soldiers, although women were officially barred from doing so.  Nevertheless, it is believed [[List of female American Civil War soldiers|hundreds of women]] disguised themselves as men in order to enlist.  While many were discovered and forced to quit, others were only found out after they were killed in combat, and a number managed to serve throughout the entire war with their true identity successfully concealed.

One of the more traditional roles played by women in the Union army was that of [[camp follower]]s.  Thousands of white and Black women accompanied Union armies in an unofficial capacity to provide their services as [[Cooking|cook]]s, [[laundress]]es, [[nurse]]s and/or [[prostitute]]s.  Many were the wives or other female relatives of the soldiers themselves who saw to their personal needs and (if time allowed) looked to the well-being of other soldiers.  A somewhat more formal role for some camp followers was that of ''[[vivandière]]''.  Originally a female [[sutler]], the role of ''vivandière'' expanded to include other responsibilities, including on the battlefield.  Armed for their own protection, they brought water to thirsty soldiers, carried the [[regimental colors]] and rallied their fellow soldiers to fight, provided [[first aid]] or helped the wounded back to a field hospital.  A related (and sometimes conflated) role was that of "daughter of the regiment".  Often literally a daughter of one of the regimental officers, these women looked to the soldiers' well-being but also served as their regiment's "mascot" who inspired the men by wearing stylish clothing and enduring the same hardships as them.  Some of the most prominent women to accompany the Union armies in the field include [[Anna Etheridge]], [[Marie Tepe]], and [[Nadine Turchin]].<ref>Cordell, M. R. (2016). Courageous Women of the Civil War: Soldiers, Spies, Medics, and More. United States: Chicago Review Press. Part IV: Vivandière</ref><ref>Tsui, B. (2006). She Went to the Field: Women Soldiers of the Civil War. United States: TwoDot. p. 73-80</ref><ref>Harper, J. E. (2004). Women During the Civil War: An Encyclopedia. Taylor & Francis. p. 53–59</ref>

Women also sought to serve more formally as nurses in the Union army, many having been inspired by the work of [[Florence Nightingale]] during the [[Crimean War]].  However, there was strong resistance against these efforts at first.  Societal prejudices saw women as too delicate and the job too unsuitable for women of social rank, particularly at the thought of unmarried women surrounded by thousands of men in close quarters.  Nevertheless, Congress eventually approved for women to serve as nurses, to which [[Dorothea Dix]] – appointed Superintendent of Army Nurses – was responsible for setting hiring guidelines and starting a training program for prospective candidates.  For the women who served, nursing during the Civil War was a hazardous occupation: grueling hours spent in close proximity to deadly diseases and nearby battlefields resulted in many suffering permanent disabilities or death.  Added to this were the prejudices of the male medical officers in charge who did not want them there and frequently clashed with the nurses over issues of [[triage]], patient treatments and [[hospice care]].  Tens of thousands of women served as nurses for the Union army, among whom are included [[Clara Barton]], [[Susie King Taylor]], [[Mary Edwards Walker]], and [[Louisa May Alcott]].<ref>Cordell (2016), Part III: Nurses</ref><ref>Harper (2004), p. 285–292</ref>

No less vital were the thousands of women who provided service to the Union army in the field of [[espionage]].  Early in the war, women were at a distinct advantage as [[Spying|spies]], [[Reconnaissance|scouts]], [[smuggler]]s, and [[saboteur]]s: the idea of women participating in such dangerous lines of work was simply not considered.  Eventually though their opponents recognized their existence, and while female spies caught in the act were not typically executed like their male colleagues, they still faced the threat of lengthy prison sentences.   For self-evident reasons many of these activities were kept secret and any documentation (if it existed) was often destroyed.  As such the identity of many of these women will never be known.  Of those who became famous for their espionage work during or after the end of the war, prominent examples include [[Harriet Tubman]], [[Mary Louvestre]], [[Pauline Cushman]], [[Elizabeth Van Lew]], and [[Mary Bowser]].<ref>Cordell (2016), Part II: Spies</ref><ref>Harper (2004), p. 348–350</ref>