Editing Union army (section)

===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>