In 1889 William F. Fox published his Regimental Losses in the American Civil War. It has become famed for listing the 300 Union units which suffered the highest casualties during the conflict, but Fox also charts the losses of those Federal formations with casualty rates outside those fabled 300. Although certain elements of the work have been revised, it still stands virtually alone as a single source for detailed Union casualty figures from the American Civil War.

Although the majority of Irishmen served in non-Irish units during the conflict, there were still a large number of ‘Irish’ regiments. The list below reproduces Fox’s figures for 21 of these regiments. Despite being interesting in and of itself, the list necessarily needs to be treated with caution. It excludes what might be regarded as non-infantry ‘Irish’ units (such as the 13th Pennsylvania Cavalry), infantry regiments that were designated as Irish but did not have large Irish numbers in the ranks (such as the 15th Maine Infantry) and infantry regiments that despite not been termed ‘Irish’ did have large Irish numbers in the ranks (such as the 42nd New York Infantry).

The 21 infantry regiments suffered a combined total of 4,808 fatalities during the American Civil War. Of these 2,277 were combat related, with a further 2,531 being due to other causes, such as illness or accident. The 69th New York of the Irish Brigade was the regiment that suffered the most fatalities, with 401 deaths. The 69th also suffered the most combat casualties, but it was the 30th Missouri that sustained the most deaths due to disease, with a staggering 280 deaths. The 9th Massachusetts and 88th New York were the most dangerous regiments to serve in as an officer, with both losing 18 officers during the conflict. Not all of the men represented by these figures were Irish, and as stated above the statistics are ultimately of somewhat limited use when studying the Irish experience of the conflict. However they do present an interesting ‘at a glance’ review of some of the more famous Irish units, and perhaps most starkly highlight the role of disease as the greatest killer of the American Civil War.

Organised

Regiment

Officers KIA/DoW

Enlisted KIA/DoW

Officers DoD/Other

Enlisted DoD/Other

Total Deaths

June

 1861

9th Massachusetts

15

194

3

66

278

December

1861

28th Massachusetts

15

235

1

136

387

September 1861

9th Connecticut

0

10

3

240

253

June

 1861

37th New York

5

69

1

37

112

August

1861

63rd New York

15

141

1

92

249

September

1861

69th New York

13

246

0

142

401

September

1861

88th New York

15

136

3

69

223

November

1862

155th New York

9

105

2

71

187

November

1862

164th New York

10

106

3

126

245

October

1862

170th New York

10

119

2

96

227

October

1862

175th New York

2

12

3

117

134

November 1862

182nd New York

8

65

0

53

126

August

1861

69th Pennsylvania

12

166

3

107

288

August

1862

116th Pennsylvania

8

137

1

88

234

June

 1861

10th Ohio

3

86

2

77

168

October

1861

35th Indiana

5

82

0

164

251

June

 1861

23rd Illinois

4

50

2

93

149

August

1862

90th Illinois

2

58

1

87

148

March

 1862

17th Wisconsin

0

41

0

228

269

June

1861

7th Missouri

4

52

2

128

186

September

1862

30th Missouri

2

10

1

280

293

TOTAL

 

157

2120

34

2497

4808

*KIA (Killed in Action), DoW (Died of Wounds), DoD (Died of Disease).

References

Fox, William F. 1889. Regimental Losses in the American Civil War 1861-1865.