Size of the Union Army in the American Civil War

Size of the Union Army in the American Civil War v1.1 draft

 

Introduction

 

The author frequently comes across quotes in books and on the internet to the effect of the Union had millions of men under arms in the Civil War. This article is an attempt to work out the actual strength of the Union Army.

 

Data

 

Livermore’s introduction states that there were 2,898,304 enlistments, including 105,693 USN/MC enlistments (all effectively “regular” enlistments) and 230,000 short term/ militia enlistments (many of which were multiple enlistments, Pennsylvania for example raised “the same” militia regiments four times, thus each man is counted 4 times) and the Navy and Marines. It is estimated that the majority of the 200,000 men who enlisted for short periods in 1861/2 reenlisted and over 200,000 veterans enlisted in the US Veteran Corps and the Veteran Regiments. In addition there were a number of “bounty hunters” who would enlist, collect their bounties and desert.

 

Thus Livermore estimates that 1,556,678 men served in the Union Army, including the militia.

 

The breakdown of enlistments was:

 

Enlistment

Number

Length (Yrs)

15th April 61

          91,816

          0.25

May-July 61

            2,715

          0.50

 

            9,147

          1.00

 

          30,950

          2.00

 

        657,898

          3.00

May-June 62

          15,007

          0.25

2nd July 62

        421,465

          3.00

4th August 62

          87,588

          0.75

15th June 63

          16,361

          0.50

July 63 draft

          35,582

          3.00

Oct 63 - Feb 64

        281,510

          1.33

14th March 64

        259,515

          3.00

23rd April 64

          83,612

          0.25

18th July 64

        385,163

          0.70

19th December 64

        211,752

          0.33

Various from territories
and the south

        172,744

          1.50

“”

         15, 509

Short Term

1865 Militia

        120,000

          0.05

 

 

 

Total

      2,898,334

              

 

Thus the number of long term (2-3 years) enlistments was 1,405,410 men, plus 14,447 existing regulars (minus those who “went south”) vs 1,082,119 Confederates with similar enlistments. In addition there were around 120,000 militia called up at various stages of the war.

 

Using the CS nomenclature of Class A (long term enlistments or “Regulars” for want of a better term), Class B (mid term enlistments for non-field duties or “Fencibles” to borrow a UK phrase) and Class C (militia) enlistments:

 

Type

Number

Fate

Class A enlistments in Apr 61

          91,816

Most reenlisted in July 61

Class A enlistments in 61-63

      1,054,079

Including the draft, but excluding reenlistees from Apr 61

Class A enlistments in 64-65

        856,430

Including reenlistments from the 61-63 batch

Class B enlistments

        454,254

At height in 63/64

Class C enlistments

        120,000

In 1865

 

The story of the number of enlistments is perhaps thus that in the first two years of the war the Union had roughly 1.1 million enlistments (excluding double counting the 90 day volunteers of 61). Of these 30,950 signed 2 year in stead of 3 year contracts, and so may be double counted if they reenlisted, this is a small number however and not likely to effect the final result. By late 1862 the US had exhausted its volunteer manpower, and turned to conscription to fill its ranks, and started enlisting blacks from the south on a fairly large scale. It also called on >200,000 men for “fencible” regiments to garrison areas.

 

It certainly appears that the US was stretched to its limit to field this large an army on a population of 21 million. Around 62/63 over 1 man in 10 was wearing a bluecoat, and if the militia etc. are included we can guess that somewhere between 1 in 4 and 1 in 5 men wore a bluecoat at some stage.

 

Strength in the Field

 

Drawing from Fox’s Regimental losses and Military History Onlines Gettysburg order of battle, it would appear that the strength of field army was approximately:

 

Corps

Subordinate to

Strength

Notes

Source

1

Army of the Potomac

      11,550

Gettysburg, Fox has 9403 only

MHO

2

Army of the Potomac

      13,000

Gettysburg, all arms

Fox

3

Army of the Potomac

      11,924

Gettysburg, all arms

Fox

4

 

            -  

Broken Up 1862, in late 1863 20 and 21
Corps merged into a new 4th Corps

Fox

5

Army of the Potomac

      10,370

Gettysburg

MHO

6

Army of the Potomac

      12,445

Gettysburg

MHO

7

Army of Virginia

      24,127

1st March 1863

Fox

8

Army of West Virginia

       7,507

10th Sept 1864

Fox

9

Army of the Ohio

       6,000

August 1863

Fox

10

Army of The James

      16,329

June 1863

Fox

11

Army of the Potomac

       8,300

Gettysburg

MHO

12

Army of the Potomac

       9,165

Gettysburg

MHO

13

Army of the Tennessee

      18,245

1st May 1863

Fox

14

Army of the Cumberland

      19,920

Chickamauga

Fox

15

Army of the Tennessee

      15,975

Spring 1863

Fox

16

Army of the Tennessee

      50,659

April 1863

Fox

17

Army of the Tennessee

      15,848

May 1863

Fox

18

Army of The James

      15,962

April 1864

Fox

19

Army of the Gulf

      35,670

April 1863

Fox

20

Army of the Cumberland

      13,779

Stone River, Jan 1863

Fox

21

Army of the Cumberland

      14,040

Chickamauga

Fox

22

Department of Washington

      25,000

 

Estimate from Letter by McClellan

23

Army of the Ohio

      10,624

31st October 1864

Fox

Cavalry

Army of the Potomac

      11,700

Gettysburg

MHO

 

 

 

 

 

Total

378139

24 and 25 Corps not formed yet

 

 

Of these 89-93% of the infantry and artillery and 83-86% of the cavalry were “not effective”, being the percentage of non-combatants and those without arms/ incapable of bearing them. The numbers above are most numbers of effectives, and usually conform to this. The exception is the massive 16th Army Corps. XVIII Corps reported that 1/3rd of its strength was ineffective, and totalled over 75,000.

 

We can thus estimate that the Union had 427,000 combatants in the field, including those ineffective at the height of the Union Army’s strength.

 

Desertion and Absenteeism

 

The Provost Marshal reported 278,644 reported desertions, although he noted that some of these may have for other reasons and by his reckoning only 201,000 of these where real desertions. However, the number of absentees is much higher than this. Absenteeism is a rather informal method of deserting. Often soldiers on leave or away sick simply choose not to return. The Absent figure includes official deserters, unofficial deserters and the genuinely absent.

 

 

Numbers on
Union Rolls

Number
Present

Number
Absent

Jul-61

      186,751

183,588

     3,163

Jan-62

      575,917

527,204

    48,713

31-Mar-62

      637,126

533,984

  103,142

01-Jan-63

      918,121

698,802

  219,319

01-Jan-64

      860,737

611,250

  249,487

01-Jan-65

      959,460

620,924

  338,536

 

Conclusion

 

The total strength of Union forces, including militias and non-combat forces peeked at about 698,000. Of these, 131,000 (approximately) were USN/ USMC and 104,000 were “fencibles” estimating a force of approximately 463,000 in the field army and home defence forces, slightly later estimates put 427,000 in the field army, so we can estimate that at around 36,000 men were involved in the services and in the militia.

 

At roughly the same time (early 63) roughly 220,000 men were absent.

 

Sources

 

Livermore, TL; “Numbers and Losses in the Civil War (1861-1865)” 2nd Ed; (1901)

http://www.carlisle.army.mil/usamhi/DL/docs/447.pdf

 

Fox, W; “Regimental Losses”; Albany Publishing Company (1889)

http://www.civilwarhome.com/foxspref.htm

 

Dyer, F; “Compendium of the Civil War”; (1908)

http://www.carlisle.army.mil/usamhi/

 

Military History Online’s Gettysburg Orbat

 

Lonn, E; Desertion in the Civil War

http://www.etymonline.com/cw/lonn.htm

 

http://carlisle-www.army.mil/usamhi/Bibliographies/ReferenceBibliographies/MilitaryService/desert/stats.doc

 

http://www.civilwarhome.com/armysize.htm

 

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