Was there an explicit three-to-one rule during the ACW for attacking an entrenched position?

The next step of interpretation would be to look at the communications between officers prior to - say - the May 10 or May 12 assaults at Spotsylvania Courthouse, the assault at Franklin, the assault on Marye's Heights, etc. and see how the generals were discussing their plans. Do plans and dispatches show evidence of a desire to gain a 3:1 attacker to defender ratio?
 
The next step of interpretation would be to look at the communications between officers prior to - say - the May 10 or May 12 assaults at Spotsylvania Courthouse, the assault at Franklin, the assault on Marye's Heights, etc. and see how the generals were discussing their plans. Do plans and dispatches show evidence of a desire to gain a 3:1 attacker to defender ratio?
I am not sure that there is anything analytical about Hood’s attack at Franklin.
 
Fair enough lol. Maybe not Franklin.

In his Cold Harbor book (I'm on the google books version so no page number), Gordon Rhea writes in the section on June 3 how Union generals criticized Grant for launching massive, army-wide assaults rather than locating and exploiting an enemy weak point. Hancock's aide Walker said, "The characteristic fault of the campaign was attacking at too many points." Grant should "discover that weak point; to make careful and serious preparation for that attack, and to mass behind the assaulting column a force that shall be irresistible, if only once the line be pierced." Instead, Grant's attacks were "weak affairs in almost every case, unsupported; and mere shoving forward of a brigade or two now here now there, like a chess player shoving out his pieces and then drawing them right back."

Wainwright wrote that, "There may have been some plan in it, but in my ignorance I cannot help but think that one big, sustained attack at one point would have been much more likely to succeed."
 
Fair enough lol. Maybe not Franklin.

In his Cold Harbor book (I'm on the google books version so no page number), Gordon Rhea writes in the section on June 3 how Union generals criticized Grant for launching massive, army-wide assaults rather than locating and exploiting an enemy weak point. Hancock's aide Walker said, "The characteristic fault of the campaign was attacking at too many points." Grant should "discover that weak point; to make careful and serious preparation for that attack, and to mass behind the assaulting column a force that shall be irresistible, if only once the line be pierced." Instead, Grant's attacks were "weak affairs in almost every case, unsupported; and mere shoving forward of a brigade or two now here now there, like a chess player shoving out his pieces and then drawing them right back."

Wainwright wrote that, "There may have been some plan in it, but in my ignorance I cannot help but think that one big, sustained attack at one point would have been much more likely to succeed."
I think you will find that Grant was doing his level best to instill an aggressive offensive spirit into the Army of the Potomac. He had also begun a ‘campaign of continuous contact,’ as modern military historians call it. It was the A of the P’s habit of contemplating their next move that gave Lee the initiative. Grant had no intention of chasing Lee around VA. His intent was to press Lee relentlessly to deprive him of any option but to respond to Grant’s pressure.

As Sherman said, Grant had no interest in what an opponent might do, he was only interested in what he was going to do to them. That the A of the P generals had a hard time wrapping their minds around what Grant was doing is no great surprise. A lot of deadwood had to be cleared out before the kind of relentless aggression Grant demanded could have effect.
 
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I can't say for certain, but the three-to-one ratio may be derived from to the writings of Clausewitz, Jomini, Napoleon, or even Frederick the Great. All would probably have been familiar to West Pointers. I suspect that the ratio was based on the number of muzzle-loading weapons it would take to overcome a similarly armed and entrenched opponent. Perhaps someone with time on their hands could track it to one of these theorists.
The last three definitely, but Clausewitz would not be translated into English until 1873. Individual commanders may have been familiar with it, however.
 
I think you will find that Grant was doing his level best to instill an aggressive offensive spirit into the Army of the Potomac. He had also begun a ‘campaign of continuous contact,’ as modern military historians call it. It was the A of the P’s habit of contemplating their next move that gave Lee the initiative. Grant had no intention of chasing Lee around VA. His intent was to press Lee relentlessly to deprive him of any option but to respond to Grant’s pressure.

As Sherman said, Grant had no interest in what an opponent might do, he was only interested in what he was going to do to them. That the A of the P generals had a hard time wrapping their minds around what Grant was doing is no great surprise. A lot of deadwood had to be cleared out before the kind of relentless aggression Grant demanded could have effect.

Haha - I'm not debating if Grant was justified in his tactics and strategies or not. I'm simply providing examples of officers suggesting some kind of desire to concentrate force against an entrenched line, perhaps to achieve a numerical superiority akin to the 3:1 rule. Perhaps it's simply the idea of hitting the weak part of the enemy's line with strength, or maybe it stems from officers' beliefs that dispersing force did not create enough of a local advantage to break through entrenchments.

Since we haven't found an explicit 3:1 comment, I'm looking for tangential references to the principle. I thought those quotes from Grant's officers seemed like a broad of saying "force parity is not enough against entrenchments, you need an advantage."

I have not read nearly enough to weigh in on a debate as to whether these officers were right or wrong in their assessment of Grant's tactics and strategy.

That being said, aggressive attitude seems more like a higher level "strategy" discussion than the nitty gritty of force ratios on the battlefield at the point of contact. One can fight aggressively while still launching concentrated attacks on the battlefield.
 
I've pulled quotes from Jomini and Napoleon. Did Frederick the Great publish some sort of maxim/rules of war book? Maybe it's in there.
I haven't looked into Frederick, but from what I tell, I don't know if he produced any writings on military tactics.
 
The last three definitely, but Clausewitz would not be translated into English until 1873. Individual commanders may have been familiar with it, however.

Halleck mentioned Clausewitz in passing in his book Elements of Military Art and Science, but there's no question that Jomini dominated the field in the early-to-mid 19th century.
 
Back in the day Vauban was criticized for his 6:1 "rule" because it was too dogmatic/artificial.

That's interesting. I've read smatterings of Vauban in secondary sources. Do you know where he propounded this rule? Was it in "A manual of siegecraft and fortification"? There is an English translation which is a little hard to get ahold of, but it is online in French.

[Later edit: I should have asked if you understood Vauban to have articulated a general rule, or whether this 6:1 ratio was in reference to a particular campaign or siege.]

R
 
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This is an interesting discussion with some excellent references that support the 3:1 rule (which also applies when playing Risk and many war traditional war games). I have always been fascinated by the number of West Point-educated Civil War commanders who served in Winfield Scott's army during the campaign against Mexico City, where US forces consistently violated the 3:1 rule and emerged victorious. Scott was outnumbered from the beginning of the campaign yet managed to navigate mountainous terrain, maintain a long supply line, and carry fortified positions at odds that sometimes were closer to 1:3 than the other way around. While the quality of the opponent had something to do with this improbable series of victories, it seems likely that many participants came away with some unwritten maxims that carried over to the Civil War, particularly among southerners: 1) superior engineering, artillery placement, and tactical precision will overcome stout defenses, and 2) aggressiveness, high morale, and the fighting qualities of the attackers can overwhelm strong positions manned by troops of equal or lesser quality. As noted throughout the thread, Lee quickly comes to mind as main proponent of the aggressiveness + elan + moral superiority school of offensive tactics, which in turn influenced the officers who served with him in both wars.
 
This is an interesting discussion with some excellent references that support the 3:1 rule (which also applies when playing Risk and many war traditional war games).

Thanks so much for adding to this discussion. It tapered off several months ago, but the 3:1 rule is still of interest to me for a writing project I'm working on. I'd still like to see an explicit articulation of that rule by some authority current or previous to the Civil War. I think there are suggestions it existed, but I wish I could find something more concrete.

Roy B.
 
The last three definitely, but Clausewitz would not be translated into English until 1873. Individual commanders may have been familiar with it, however.
Gen Willich, for example, was a cadet at the Prussian military academy while Clausewitz was the commander. He had been schooled in Clausewitz’s principles by the man himself. His 20 years of service would have instilled an encyclopedic knowledge of the great man’s principles.
 
I too was a wargamer for many years, and the 3-to-1 rule was always considered a basic tenet of most of the games. Of course I always took the rule to mean include the condition, "all other factors being equal." That last qualifier is rarely the case in battle. As has been well-stated by others, factors such as leadership ability, morale, quality of weapons, etc., always come into play. I have never known who derived the basic rule in history.
 
Gen Willich, for example, was a cadet at the Prussian military academy while Clausewitz was the commander. He had been schooled in Clausewitz’s principles by the man himself. His 20 years of service would have instilled an encyclopedic knowledge of the great man’s principles.

I doubt that. Clausewitz was director of the General War School in Berlin 1818-30, which trained generals and their staff officers, and had nothing to do with junior officer education. Entrance was competitive, and three years regimental service as an officer was the minimum requirement to enter. The minimum age was thus 25-26, and when Willich was 25, Clausewitz had both left the General War School, and died.

Further, Clausewitz's On War (which he wrote most of in 1827) was published posthumously.

Willich was sent to the Military Orphanage in Potsdam at age 12, which was one for 3 or 4 junior military schools. At age 15 he was one of the few selected to go to the Cadet School in Berlin, which had three more years of schooling.

From here there were three routes to Commissioning:

1. A small group (30) of the finalists at the Cadet School were selected to stay on for an additional year (the selecta), and if they passed would enter the army directly as second lieutenants at the age of 19.
2. After 9 months service as an enlisted man in an artillery or engineer unit, a graduate of the Cadet School (or a volunteer endorsed by the colonel) could apply to enter the Combined Artillery and Engineers School. This course of study is three years, and at the end of the first year the student sits the examination for ensign. If they pass they are commissioned as an ensign and continue into the second year. If they fail they are returned to unit as an enlisted man. At the end of the three year course they are examined for a second lieutenancy and Commissioned such if they pass.
3. After nine months service as an enlisted man, graduates of the Cadet School or volunteers endorsed by their colonel, could apply to the nine-month course of instruction at a Division School, at the end of which they were examined for a second lieutenancy in their parent regiment.

The Cadet Schools were just schools in the conventional sense, like a British public school. Only the selecta were uniformed and subjected to military discipline (having already passed the exam for an ensigncy, and being made such).

Since Willich was an undistinguished artillery officer, I assume he entered the Combined Artillery and Engineer School around 19, and Commissioned as 2Lt at 22. When Clausewitz was assigned to regimental duty in 1830, Willich was probably a freshman at the Combined School.
 
Further, whilst Willich is often called a captain, in 1848 he was the 1st Lt of 4th company, 7th artillery brigade. Checking earlier editions, in 1841 he was in the same position and rank. In 1829 he is listed as 2Lt of the 1st coy. I guess he must have been in the selecta for that year. In 1840 he is the lowest ranked 1Lt in his bde, and so just promoted.

A check of the staff of the Cadet School in 1828 shows that one of the teachers was 2Lt von Clausewitz. I suspect what has happened is that 2Lt and Gen v. Clausewitz have been confused.
 
Thanks so much for adding to this discussion. It tapered off several months ago, but the 3:1 rule is still of interest to me for a writing project I'm working on. I'd still like to see an explicit articulation of that rule by some authority current or previous to the Civil War. I think there are suggestions it existed, but I wish I could find something more concrete.

Roy B.
I don't think you are likely to find anything specific about a 3:1 combat rule before the American Civil War.

Clausewitz talks about numbers in war, but he is dealing essentially in the period of Frederick the Great and Napoleon as it applies to the Prussian Army after the Napoleonic Wars. He had not yet finished Vom Krieg ("On War") when he died in 1831 (his wife cleaned up what he had done and published the work). If Clausewitz had lived, it would have been longer than 10 volumes. He was in the process of pulling together and tidying up his old manuscripts but had not gotten around to all of them or to his extensive correspondence with other authorities and military experts.

This would also mean, for example, that Clausewitz is writing before the mass adoption of the percussion cap to military firearms (increases infantry firepower about 5-10% by reducing misfires), the mass adoption of the Minie-style rifle, and the mass adoption of rifled artillery. It was a student of Clausewitz's theories, Helmuth von Moltke "the Elder" (the man they named the "Age of Moltke" after), who would decide that firepower was now more important than shock combat in his 1860 study of the 1859 War in Italy between France and Austria. Clausewitz's work is not dependent on those things and is not generally changed by them -- but Clausewitz's work is not really about hard-and-fast rules to apply to war.

Most of the real mathematical models pivot around the work of Frederick Lanchester ("Lanchester's Square Law") during World War I. The 3:1 Rule starts showing up in US Army manuals after World War II.
 
I don't think you are likely to find anything specific about a 3:1 combat rule before the American Civil War.

Clausewitz talks about numbers in war, but he is dealing essentially in the period of Frederick the Great and Napoleon as it applies to the Prussian Army after the Napoleonic Wars. He had not yet finished Vom Krieg ("On War") when he died in 1831 (his wife cleaned up what he had done and published the work). If Clausewitz had lived, it would have been longer than 10 volumes. He was in the process of pulling together and tidying up his old manuscripts but had not gotten around to all of them or to his extensive correspondence with other authorities and military experts.

This would also mean, for example, that Clausewitz is writing before the mass adoption of the percussion cap to military firearms (increases infantry firepower about 5-10% by reducing misfires), the mass adoption of the Minie-style rifle, and the mass adoption of rifled artillery. It was a student of Clausewitz's theories, Helmuth von Moltke "the Elder" (the man they named the "Age of Moltke" after), who would decide that firepower was now more important than shock combat in his 1860 study of the 1859 War in Italy between France and Austria. Clausewitz's work is not dependent on those things and is not generally changed by them -- but Clausewitz's work is not really about hard-and-fast rules to apply to war.

Most of the real mathematical models pivot around the work of Frederick Lanchester ("Lanchester's Square Law") during World War I. The 3:1 Rule starts showing up in US Army manuals after World War II.
Just by way of amplification, the Lanchester "rule" is usually conditioned on the relative quality of the two forces, the details of evaluating the respective sides' assets brought to bear in the specific engagement, and the element of surprise.
 
Thanks so much for adding to this discussion. It tapered off several months ago, but the 3:1 rule is still of interest to me for a writing project I'm working on. I'd still like to see an explicit articulation of that rule by some authority current or previous to the Civil War. I think there are suggestions it existed, but I wish I could find something more concrete.

Roy B.

It is also worth noting that the 3:1 Rule for combat is not about raw numbers of troops. It is about units of combat power (which is what Lanchester is talking about in "Lanchester's Square Law" during WWI).

If 1,000 infantrymen equals one unit of combat power in all cases, life would be simple and the 3:1 Rule would be easy to apply. Unfortunately for simple rules, life is rarely simple and combat is even worse. You need an incredible amount of detail on subjects that are often not obvious or easily quantifiable to do the calculations. There are what modern military theory refers to as force multipliers to consider.

It makes a difference, for instance, if the defender is dug in to a prepared position. The saying in the days of the Civil War was roughly "one man in a trench with a rifle is worth three in the open". As a general rule, that is a fairly practical one for tactical infantry combat in 1864-65. If you are getting ready to make a head-on assault on an entrenched line across open ground, that is a great rule of thumb.

Now suppose you have a lot of superior artillery (say Union 3" rifles) in a good position that can enfilade the defender and shell him out of his trenches. Maybe that 3:1 Rule no longer applies. This explains why Hood and Polk argue for pulling out of the trenches at Cassville in the Atlanta Campaign (Johnston's report: "Soon after dark Lieutenant-Generals Polk and Hood together expressed to me decidedly the opinion formed upon the observation of the afternoon, that the Federal artillery would render their positions untenable the next day, and urged me to abandon the ground immediately and cross the Etowah.") Sherman has nothing like a 3:1 troop superiority, but experienced generals feel the 3:1 Rule is not applicable at Cassville.

Suppose you are in a meeting engagement, not an attack on an entrenched position? No trenches involved, just troops running into one another while on the move? Do you need a 3:1 advantage to successfully attack? Or will acting aggressively and striking first mean more?

Also, the 3:1 Rule is really all about local advantages at the point of attack. A smaller army can achieve a local advantage by moving quickly, concentrating a superior force against a fraction of the larger foe. This is an essentialJomini concept:

"There is one great principle underlying all the operations of war… It is embraced in the following maxims: (1) To throw by strategic movements the mass of an army, successively, upon the decisive points of a theater of war, and also upon the communications of the enemy as much as possible without compromising one's own. (2) To maneuver to engage fractions of the hostile army with the bulk of one's own forces. (3) On the battlefield, to throw the mass of the forces upon the decisive point, or upon that portion of the hostile line which it is of the first importance to overthrow. (4) To so arrange that these masses shall not only be thrown upon the decisive point, but that they shall engage at the proper times and with energy."​

This is what Lee strove to do, and Grant, and McClellan, and many others. The skill and luck with which they did it -- as well as the skill and luck with which their opponents countered their attempts -- is what comes out in history as success and failure.
 
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