Livermore v. Dupuy: Analyzing the Relative Performance of Civil War Opponents

All students of the American Civil War should read Thomas L. Livermore's Numbers and Losses in the Civil War in America, 1861-1865 and T. N. Dupuy's A Genius for War.  Both provide comparisons and methods for analyzing the intensity of particular fights and the performance of the troops involved.

Livermore analyzes according to hits in 1,000 (casualties suffered) and hits by 1,000 (casualties inflicted).  The former figure, hits in 1,000, gives a perspective on what the troops endured, similar to what William F. Fox, in Regimental Losses in the American Civil War, 1861-1865 has in mind when he defines his fighting 300 Federal regiments on the basis of more than 130 or ten percent killed or mortally wounded and then gives charts of Confederate units that lost more than forty percent in particular fights.  The latter figure, hits by 1,000, shows how efficiently the troops performed in damaging the foe--perhaps the more important figure.  

Dupuy incorporates Livermore's analysis and takes it a couple steps further.  First, Dupuy figures out the raw performance of the troops with reference to one another.  That is, for example, the hits by 100 of one side divided by the hits by 100 of the other, and vice versa.  In a longer operation, this is broken down into the casualties inflicted per dayIn "Table 4: Combat Efficiency" below, from my Siege of Petersburg: The Battles for the Weldon Railroad, August 1864, those percentages are in parenthesis.  As you can see, General Lee's army substantially outperformed General Grant's army in August, 1864.  (Beringer, Hattaway, Jones, and Still go this far in Why The South Lost The Civil War.)  Finally, Dupuy modifies the scores for the posture of the forces involved--Attack and Hasty Defense divides by 1.2, Hasty Defense by 1.3, Prepared Defense by 1.5, Fortified Defense by 1.6.  That gives the final column in the table below, "Score Effectiveness."  

Livermore is thus a very helpful starting point, but for actions that lasted no more than a single day, such as Second Reams Station below, one ought to go further and calculate the relative performance of the troops (Why The South Lost The Civil War does this) as modified by the posture of the troops (using Dupuy's formula).  If you look at Dupuy, you will see that the intensity of American Civil War actions exceeds the limits of the examples on his charts, which come from World War I and World War II.  (See note 3, below.)  The full Dupuy analysis is the most helpful for analyzing performance in longer operations, such as the Fourth Offensive as a whole, below.  

TABLE 4:  COMBAT EFFICIENCY

Fourth Offensive

                                                                                                                                                                                                                                                                                     Casualties

                                                                  Average           Percent            Inflicted

No. of        Total               Total                Casualties        Casualties        Per Day               Score

Battles       Engaged         Casualties        per day (12)      Per Day           Per 100 Men[1]  Eff.[2]

USA    3    85,877            9,922                827                   0.96                 0.4 (  28.5%)       0.33

CSA    3    56,795            4.500                375                   0.66                 1.4 (350%)          1.16

Second Reams Station

                                                                                   

                                                                                    Casualties

            Total                Total                Percent            Inflicted                       Score

            Engaged          Casualties        Casualties        Per 100 Men                Effectiveness[3]

USA    8,000               2,727               34.0                    9.375 (  27.5%)            6.25 (  18.4%)

CSA    8,000                  750                 9.375              34.0     (363%)             34.0   (544%) 

---

[1] This column corresponds to Dupuy’s “Score” and represents “the casualties per day as a percentage of the force inflicting the casualties, derived by applying the casualties of one side to the starting or overall strength of the other side.” Dupuy, A Genius for War, 328.  The figure in parenthesis represents one side’s “Score” or combat efficiency as a percentage of the “Score” of the other side.  The Unionists (at 28.5% of the Confederates) had fallen a long way from the combat efficiency displayed at Antietam (61% of the defending Rebels), while the Secessionists (at 350% of the Federals) performed better than at Gettysburg (100% of the defending Northerners).  Beringer, Hattaway, Jones, and Still, Why The South Lost The Civil War, 472.   Dupuy displays an alternate “Score” excluding prisoners.  Dupuy, A Genius for War, 330-331.  I have not shown an alternate “Score” excluding prisoners because in the campaign of 1864 a prisoner amounted to a dead man due to Grant’s refusal to exchange prisoners.

[2] “This last column, ‘Score Effectiveness,’ adjusts the Score value to reflect approximately the known operational advantage which is conferred by defensive posture. “  Ibid., 328.  Because both sides attacked and at least partially engaged also in hasty defense during Grant’s fourth offensive at Petersburg, I have applied the operational advantage of 1.2 estimated by Dupuy for such situations.  Ibid.  Looking at Dupuy’s Figure C-1/Aggregated Statistics of Fifteen World War I Battles, Grant’s fourth offensive most resembles in its results 1915’s forty-five day long Champaign II battle, where with the benefit of machine guns and modern artillery the defending Germans attained a score effectiveness of 1.06 and the attacking French had a score effectiveness of 0.27.  Ibid., 330-331.  The fifteen day Aisne II (Nivelle offensive) where the defending Germans had a score effectiveness of 1.03 and the attacking French attained a score effectiveness of 0.27, may provide a better example because of a length similar to Grant’s fourth offensive and the tendency of score effectiveness to drop as battles drag on.  Ibid., 328-331.

[3] This column adjusts score effectiveness at Second Reams Station by 1.5 for the Prepared Defense of the Federals.  Ibid., 328.  It did not amount to a Fortified Defense which would have required an adjustment by 1.6 because the Unionists failed to improve the Reams Station earthworks significantly.  Id.  Even giving the Federals every benefit of the doubt and adjusting by 1.3 for a Hasty Defense, they attained a Score Effectiveness of 7.21.  Either way, the Unionists scored surprisingly well at Second Reams Station—just not very well in relation to the Confederates.  Whether the Federals attained a score effectiveness of 6.25 or 7.21, their score effectiveness resembles that of the victorious Germans in 1914’s battle of the Masurian Lakes.  Ibid., 330-331.  Unfortunately for the Northerners at Second Reams Station, the victorious Rebels attained a far higher score effectiveness of 34.0, approaching the 38.1 of the victorious Germans in 1915’s battle of Gorlice-Tarnow.  Ibid.  Dupuy’s chart does not list a battle where the defeated attained a score effectiveness above the 3.86 of the Germans in 1914’s Marne battle.  Ibid.  The score effectiveness of the armies for the entire fourth offensive gives a better idea of their capacities compared to WWI troops than the score effectiveness for the single day’s combat at Second Reams Station.  Ibid., 329-331.

Interview About My Library

Spotlight on . . . Author John Horn's Library

This month we turn back to an author library spotlight by taking a look at the library of John Horn, author of The Siege of Petersburg: The Battles for the Weldon Railroad, August 1864. ********** Q: Roughly how many books do you have in your collection? A: Our library contains a couple thousand books. It includes volumes on the warfare of all eras. I have fewer than a hundred books on the Civil War. Q: When did you start your collection? A: I began to contribute to my family's collection while I was in grammar school. My father had begun his collection, judging from the inscriptions in his books, in the Fifties after he married my mother. I inherited his collection in the Nineties. Q: What does your wife think of your library? A: Part of my family's collection belongs to my wife, who is also my law partner. She comes from Richmond, Virginia. She is connected with how I began to write about the Civil War. Her grandmother asked me to trace their family back as far as I could. In doing so, I found soldiers from the Revolutionary War, the War of 1812, and the Civil War. I became interested in Colonial Virginia first and collected books on that. I also acquired volumes on Petersburg, Dinwiddie County, and Brunswick County, where her ancestors had settled, and she approved of those. Only when I began writing books about the Civil War in the late Eighties did I begin to collect books about it.  Q: How many times have you had to move with the library? A: My family moved as I entered eighth grade and again while I was away at law school in New York. Some volumes disappeared in these moves, including Three Lights from a Match, an unforgettable group of stories about World War I by Leonard H. Nason. The first move was in 1984, to cart my collection about five miles across town from my parents' house to the house my wife and I had bought. Shortly afterward, my wife and I moved her collection about twenty-five miles from downtown Chicago to our house. The biggest move was in 1995 to transport my father's collection across town to my house after he and my mother had died. The moves across town were easy. Moving my wife out from Chicago was difficult. We moved her out on the coldest night in Chicago history, twenty-six below. The moving van broke down on the Dan Ryan Expressway. The movers got drunk. The van had to be towed out to our house. Her plants died and it seemed to take weeks for the house to warm up, but her books survived. Q: What's your most prized book? A: Richmond Redeemed: The Siege at Petersburg. It contains the following inscription by Dr. Sommers, whom I regard as the standard setter for research in the field:  To John Horn

More praise for "The Siege of Petersburg: The Battles for the Weldon Railroad"

I hope the book is selling well: it is an excellent campaign history, full of clear explanation, dramatic stories, and incisive analysis.  I especially appreciated the summary chapter, where Horn gave evaluations of all the key players.

--Dr. John G. Selby, author of Virginians at War 

The Confederate Alamo: Bloodbath at Petersburg’s Fort Gregg on April 2, 1865

I enjoyed very much reading John J. Fox’s The Confederate Alamo and recommend it to any student of the Siege of Petersburg.  The book tells vividly the story of the Federal assault on Fort Gregg, just southwest of Petersburg, on April 2, 1865.  The prose is vigorous, the book hard to put down.  It is unusually well illustrated and the maps are very helpful.  It ought to have taken a couple of paragraphs to describe the Confederate attack on Fort Stedman of March 25, 1865, together with the same day’s Unionist counterattack on the Secessionist picket line between Petersburg and Hatcher’s Run.  The capture of the Rebel picket line there made possible the successful assault of the Northern VI Corps on the Confederate lines southwest of Petersburg just prior to the storming of Fort Gregg by the Federal XXIV Corps.   Early on there is an arithmetical mistake where 300 to 4500 is said to be 13 to 1, but later in the text it is clear that what was meant was 330 to 4500, which is about 13 to 1.  A few minor factual errors occur.  Brig. Gen. Robert S. Foster had not spent the previous summer in the Shenandoah but around Deep Bottom on James River.  Battery 45 of the Dimmock Line, the main belt of Rebel fortifications around Petersburg, was not Fort Mahone; battery 29 was Fort Mahone, known to the Unionists as Fort Damnation.  There was not one Georgia Brigade in Hood’s Old Division at this point; there were two, Benning’s and G. T. Anderson’s.  The question of why not bypass Fort Gregg merited a lengthier discussion.  There is a slight redundancy in twice introducing Maj. George H. Stowitz, an officer who played a role in the assault on Fort Gregg and the author of a good history of the 100th New York.  Despite these minor problems, The Confederate Alamo  is a great read and most helpful understanding the bitter fighting that took place at Fort Gregg on April 2, 1865.  Should there be a second edition, I have a copy of a pension application indicating there may have been a second Southern soldier to have escaped death or captivity at Fort Gregg.  This edition is welcome on my shelf for books about the Siege of Petersburg.

Grandfather's Journal: Company B, Sixteenth Mississippi Infantry Volunteers, Harris' Brigade, Mahone's Division, Hill's Corps, A.N.V., May 27, 1861-July 15, 1865

When this book came out in 1988, it was radioactive.  All knew that it had an undefined fictional component and was unreliable.  It would not be so bad if we knew what was fiction, what was fact, but we do not.  The journal in question was admittedly minimal, much of the rest fictional.  Read the Preface.  The rest is a reconstruction.  Over the years, as print has given way to the internet, people have forgotten that this is not grandfather's journal but a reconstruction of it.  I see more and more histories, some quite good, citing this fabrication.  At best this can be called a history of Company B, 16th Mississippi Infantry.  At worst, it is a fraud.  Steer clear of it unless you are willing to take it with many grains of salt.  If the author had clearly separated the genuine from the reconstructed, matters would be different.