Special Report

Union Army Regiments That Suffered the Most Losses in the Civil War

MPI / Archive Photos via Getty Images

During the Revolutionary War, an estimated 25,000 American service members sacrificed their lives to gain independence from Great Britain. Less than a century later, the fight to preserve the country proved far costlier. Nearly 620,000 Americans were killed in the Civil War, more than in any war involving the United States, before or since. 

Over the four years of the American Civil War – from 1861 to 1865 – the majority of military casualties were suffered by Union forces. To maintain the integrity of the Union, federalist states and territories in the Northeast, Midwest, and West Coast mobilzed nearly 2.7 million troops – 360,222 of whom would not return home, compared to an estimated 258,000 Confederate fatalities. 

While the conflict drew resources and manpower from nearly every corner of the divided nation, regiments from certain parts of the country suffered unusually high numbers of casualties, reporting battlefield losses in the hundreds with hundreds more dying from disease. 

Using data from A Compendium of the War of the Rebellion by Civil War statistician Frederick H. Dyer, first published in 1908, 24/7 Wall St. identified the Union regiments that suffered the most losses in the Civil War. Regiments are ranked by the total number of officers and enlistees who were either killed or mortally wounded in combat. Due to incomplete and missing data, Confederate regiments were not considered.

Newly formed Union regiments in the Civil War were typically made up of about 1,000 troops – 970 enlistees and 30 officers. In each regiment on this list, more than 200 soldiers were killed or mortally wounded in battle. Including death from disease, total fatality counts exceed 600 in some cases. (Here is a look at the states with the highest Civil War death toll.)

The high casualty rates in these regiments are often attributable to their involvement in some of the bloodiest and most devastating battles of the war. Many of these regiments were fielded at one or more of the deadliest engagements of the war, including the Battle of Gettysburg, the Battle of Spotsylvania Courthouse, the Battle of the Wilderness, and the Battle of Antietam, where Union casualties (including wounded) ranged from about 12,000 to 23,000 in each battle. (Here is a look at the most violent Civil War battles.)

The regiments on this list are from states across the Northeast and Midwest, though New York and Pennsylvania were each home to seven, the most of any state. New York and Pennsylvania also supplied more troops for the war effort than any state on either side of the conflict. 

Click here to see the Union Army regiments that suffered the most losses in the Civil War.

Click here to read our detailed methodology.

Source: Kean Collection / Archive Photos via Getty Images

30. 2nd Vermont Volunteer Infantry Regiment
> Killed in battle: 224 soldiers (6 officers, 218 enlisted troops)
> Killed by disease: 175 soldiers (0 officers, 175 enlisted troops)
> Regiment formed in: Burlington, VT in 1861
> Notable battles: Battle of Bull Run, Battle of Williamsburg, Battle of Antietam, Battle of Fredericksburg, Battle of Gettysburg, Battle of the Wilderness, Spotsylvania Court House, Cold Harbor

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Source: Rischgitz / Hulton Archive via Getty Images

29. 100th Pennsylvania Volunteer Infantry Regiment “Roundheads”
> Killed in battle: 224 soldiers (16 officers, 208 enlisted troops)
> Killed by disease: 185 soldiers (2 officers, 183 enlisted troops)
> Regiment formed in: Pittsburg, PA in 1861
> Notable battles: Battle of South Mountain, Battle of Antietam, Battle of Fredericksburg, Battle of the Wilderness, Battle of Spotsylvania Court House, Cold Harbor

Source: Public Domain / Wikimedia Commons

28. 2nd Michigan Volunteer Infantry Regiment
> Killed in battle: 225 soldiers (11 officers, 214 enlisted troops)
> Killed by disease: 147 soldiers (4 officers, 143 enlisted troops)
> Regiment formed in: Detroit, MI in 1861
> Notable battles: Battle of Williamsburg, Battle of Seven Pines, Second Battle of Bull Run, Battle of Fredericksburg, Siege of Knoxville, Battle of the Wilderness, First Assault on Petersburg, Assault on and fall of Petersburg

Source: Public Domain / Wikimedia Commons

27. 27th Michigan Volunteer Infantry Regiment
> Killed in battle: 225 soldiers (10 officers, 215 enlisted troops)
> Killed by disease: 207 soldiers (3 officers, 204 enlisted troops)
> Regiment formed in: Port Huron, Ovid, and Ypsilanti, MI in 1863
> Notable battles: Siege of Vicksburg, Siege of Knoxville, Battle of the Wilderness, Spotsylvania Court House, Cold Harbor

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Source: Public Domain / Wikimedia Commons

26. 121st New York Infantry Regiment
> Killed in battle: 226 soldiers (14 officers, 212 enlisted troops)
> Killed by disease: 121 soldiers (4 officers, 117 enlisted troops)
> Regiment formed in: Herkimer, NY in 1862
> Notable battles: Salem Heights, Battle of Gettysburg, Rappahannock Station, Battle of the Wilderness, Spotsylvania Court House, Battle of Cedar Creek

Source: Public Domain / Wikimedia Commons

25. 14th New York Heavy Artillery
> Killed in battle: 226 soldiers (6 officers, 220 enlisted troops)
> Killed by disease: 301 soldiers (2 officers, 299 enlisted troops)
> Regiment formed in: Rochester and Elmira, NY in 1863 and 1864
> Notable battles: Rapidan Campaign, Battle of the Wilderness, Spotsylvania Court House, First Assault on Petersburg

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Source: library_of_congress / Flickr

24. 2nd Pennsylvania Heavy Artillery Regiment
> Killed in battle: 226 soldiers (5 officers, 221 enlisted troops)
> Killed by disease: 390 soldiers (5 officers, 385 enlisted troops)
> Regiment formed in: Philadelphia, PA in 1862
> Notable battles: Assault on Petersburg, Cold Harbor, Chaffin’s Farm, New Market Heights

Source: Public Domain / Wikimedia Commons

23. 45th Pennsylvania Volunteer Infantry Regiment
> Killed in battle: 227 soldiers (13 officers, 214 enlisted troops)
> Killed by disease: 252 soldiers (0 officers, 252 enlisted troops)
> Regiment formed in: Harrisburg, PA in 1861
> Notable battles: Battle of South Mountain, Battle of Antietam, Battle of the Wilderness, Battle of Spotsylvania Court House, Assault on and fall of Petersburg

Source: Public Domain / Wikimedia Commons

22. 48th New York Volunteer Infantry Regiment “Continental Guard” or “Perry’s Saints”
> Killed in battle: 236 soldiers (18 officers, 218 enlisted troops)
> Killed by disease: 133 soldiers (2 officers, 131 enlisted troops)
> Regiment formed in: Brooklyn, NY in 1861
> Notable battles: Assaults on Fort Wagner, Attack on Morris Island,

Battle of Olustee, Battle of Drury’s Bluffs, Capture of Wilmington

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Source: Public Domain / Wikimedia Commons

21. 11th Pennsylvania Volunteer Infantry Regiment
> Killed in battle: 236 soldiers (12 officers, 224 enlisted troops)
> Killed by disease: 181 soldiers (4 officers, 177 enlisted troops)
> Regiment formed in: Harrisburg and Westmoreland County, PA in 1861
> Notable battles: Second Battle of Bull Run, Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness

Source: Public Domain / Wikimedia Commons

20. 61st Pennsylvania Volunteer Infantry Regiment
> Killed in battle: 237 soldiers (19 officers, 218 enlisted troops)
> Killed by disease: 101 soldiers (1 officer, 100 enlisted troops)
> Regiment formed in: Pittsburg, PA in 1861
> Notable battles: Battle of Seven Pines, Battle of Fredericksburg, Battle of Salem Heights, Battle of Gettysburg, Battle of the Wilderness, Battle of Spotsylvania Court House, Battle of Cedar Creek

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Source: Public Domain / Wikimedia Commons

19. 2nd Wisconsin Volunteer Infantry Regiment
> Killed in battle: 238 soldiers (10 officers, 228 enlisted troops)
> Killed by disease: 77 soldiers (0 officers, 77 enlisted troops)
> Regiment formed in: Madison, WI in 1861
> Notable battles: Battle of Bull Run, Battle of Groveton, Second Battle of Bull Run, Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg

Source: Archive Photos / Archive Photos via Getty Images

18. 40th New York Infantry Regiment “Mozart Regiment”
> Killed in battle: 238 soldiers (10 officers, 228 enlisted troops)
> Killed by disease: 172 soldiers (2 officers, 170 enlisted troops)
> Regiment formed in: Yonkers, NY in 1861
> Notable battles: Battle of Williamsburg, Battle of Seven Pines, Battle of Bull Run, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Spotsylvania Court House

17. 15th New Jersey Volunteer Infantry Regiment
> Killed in battle: 240 soldiers (8 officers, 232 enlisted troops)
> Killed by disease: 132 soldiers (1 officer, 131 enlisted troops)
> Regiment formed in: Camp Fair Oaks, NJ in 1862
> Notable battles: Battle of Fredericksburg, Battle of Salem Heights, Battle of Gettysburg, Assault on the Salient, Battle of Cold Harbor, Battle of Cedar Creek

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Source: Fotosearch / Archive Photos via Getty Images

16. 15th Massachusetts Volunteer Infantry Regiment
> Killed in battle: 241 soldiers (14 officers, 227 enlisted troops)
> Killed by disease: 122 soldiers (1 officer, 121 enlisted troops)
> Regiment formed in: Worcester County, MA in 1861
> Notable battles: Action at Ball’s Bluff, Battle of Antietam, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor

Source: Public Domain / Wikimedia Commons

15. 1st Massachusetts Heavy Artillery Regiment
> Killed in battle: 241 soldiers (9 officers, 232 enlisted troops)
> Killed by disease: 243 soldiers (2 officers, 241 enlisted troops)
> Regiment formed in: Essex County, MA in 1861
> Notable battles: Battle of Spotsylvania Court House, Battle of Harris Farm, Siege of Petersburg

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Source: Public Domain / Wikimedia Commons

14. 6th Wisconsin Volunteer Infantry Regiment
> Killed in battle: 244 soldiers (16 officers, 228 enlisted troops)
> Killed by disease: 113 soldiers (1 officer, 112 enlisted troops)
> Regiment formed in: Madison, WI in 1861
> Notable battles: Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor

Source: Public Domain / Wikimedia Commons

13. 105th Pennsylvania Infantry Regiment “Wild Cat Regiment”
> Killed in battle: 245 soldiers (14 officers, 231 enlisted troops)
> Killed by disease: 140 soldiers (1 officer, 139 enlisted troops)
> Regiment formed in: Pittsburg, PA in 1861
> Notable battles: Second Battle of Bull Run, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor

Source: Public Domain / Wikimedia Commons

12. 16th Michigan Michigan Volunteer Infantry Regiment “Stockton’s Independent Regiment”
> Killed in battle: 247 soldiers (12 officers, 235 enlisted troops)
> Killed by disease: 143 soldiers (0 officers, 143 enlisted troops)
> Regiment formed in: Plymouth and Detroit, MI in 1861
> Notable battles: Second Battle of Bull Run, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor

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Source: Public Domain / Wikimedia Commons

11. 28th Massachusetts Volunteer Infantry Regiment
> Killed in battle: 250 soldiers (15 officers, 235 enlisted troops)
> Killed by disease: 137 soldiers (1 officer, 136 enlisted troops)
> Regiment formed in: Cambridge and Boston, MA in 1861
> Notable battles: Second Battle of Bull Run, Battle of Chantilly, Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg

Source: Public Domain / Wikimedia Commons

10. 2nd Connecticut Heavy Artillery Regiment
> Killed in battle: 254 soldiers (12 officers, 242 enlisted troops)
> Killed by disease: 173 soldiers (2 officers, 171 enlisted troops)
> Regiment formed in: Washington, D.C. in 1863
> Notable battles: Battle of Spotsylvania Court House, Battle of Cold Harbor, Siege of Petersburg, Battle of Cedar Creek, Appomattox Court House

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Source: Archive Photos / Archive Photos via Getty Images

9. 69th New York Volunteer Infantry Regiment
> Killed in battle: 259 soldiers (13 officers, 246 enlisted troops)
> Killed by disease: 142 soldiers (0 officers, 142 enlisted troops)
> Regiment formed in: New York, NY in 1861
> Notable battles: Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor

Source: Public Domain / Wikimedia Commons

8. 20th Massachusetts Volunteer Infantry Regiment “Harvard Regiment”
> Killed in battle: 260 soldiers (17 officers, 243 enlisted troops)
> Killed by disease: 149 soldiers (1 officer, 148 enlisted troops)
> Regiment formed in: Readville, MA in 1861
> Notable battles: Battle of Antietam, Battle of Fredericksburg, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor, Siege of Petersburg, Appomattox Court House

7. 5th Michigan Michigan Volunteer Infantry Regiment
> Killed in battle: 263 soldiers (16 officers, 247 enlisted troops)
> Killed by disease: 191 soldiers (3 officers, 188 enlisted troops)
> Regiment formed in: Detroit, MI in 1861
> Notable battles: Second Battle of Bull Run, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor, Appomattox Court House

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Source: Public Domain / Wikimedia Commons

6. 7th Wisconsin Volunteer Infantry Regiment
> Killed in battle: 281 soldiers (10 officers, 271 enlisted troops)
> Killed by disease: 143 soldiers (0 officers, 143 enlisted troops)
> Regiment formed in: Madison, WI in 1861
> Notable battles: Second Battle of Bull Run, Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor, Appomattox Court House

Source: exit78 / Flickr

5. 83rd Pennsylvania Volunteer Infantry Regiment
> Killed in battle: 282 soldiers (11 officers, 271 enlisted troops)
> Killed by disease: 153 soldiers (2 officers, 151 enlisted troops)
> Regiment formed in: Erie, PA in 1861
> Notable battles: Second Battle of Bull Run, Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of the Wilderness, Battle of Cold Harbor, Appomattox Court House

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Source: Public Domain / Wikimedia Commons

4. 7th New York Heavy Artillery “Albany County Regiment” or “Seymour Guard”
> Killed in battle: 291 soldiers (14 officers, 277 enlisted troops)
> Killed by disease: 378 soldiers (4 officers, 374 enlisted troops)
> Regiment formed in: Albany, NY in 1862
> Notable battles: First Assault on Petersburg, Hatcher’s Run

Source: Public Domain / Wikimedia Commons

3. 5th New Hampshire Volunteer Infantry Regiment
> Killed in battle: 295 soldiers (18 officers, 277 enlisted troops)
> Killed by disease: 178 soldiers (2 officers, 176 enlisted troops)
> Regiment formed in: Concord, NH in 1861
> Notable battles: Battle of Antietam, Battle of Fredericksburg, Battle of Chancellorsville, Battle of Gettysburg, Battle of Cold Harbor

Source: Public Domain / Wikimedia Commons

2. 8th New York Heavy Artillery
> Killed in battle: 361 soldiers (19 officers, 342 enlisted troops)
> Killed by disease: 302 soldiers (4 officers, 298 enlisted troops)
> Regiment formed in: Lockport, NY in 1862
> Notable battles: Battle of Cold Harbor, Siege of Petersburg, Appomattox Court House

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Source: Public Domain / Wikimedia Commons

1. 1st Maine Heavy Artillery Regiment
> Killed in battle: 423 soldiers (23 officers, 400 enlisted troops)
> Killed by disease: 260 soldiers (0 officers, 260 enlisted troops)
> Regiment formed in: Bangor, ME in 1862
> Notable battles: Battle of Cold Harbor, Siege of Petersburg, Second Battle of Deep Bottom

Methodology

To identify the Union regiments that suffered the most losses in the Civil War, 24/7 Wall St. reviewed data from A Compendium of the War of the Rebellion by Civil War statistician Frederick H. Dyer, first published in 1908. Regiments are ranked by the total number of officers and enlistees who were either killed or mortally wounded in combat. Due to incomplete and missing data, Confederate regiments were not considered.

We considered each of the nearly 900 Union regiments that lost 50 or more soldiers in battle. In the case of a tie in combat deaths, the regiment that lost more soldiers to disease ranks higher. 

Supplemental data on when and where each regiment was formed, and on the major battles they were involved in, came from Battle Unit Details reports compiled by the National Park Service.

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