Why were Civil War battle techniques so bloody, if the US had learned guerrilla fighting in the Revolutionary War?

Whilst it's an interesting topic, unfortunately, the questions, answers, definitions and many facts are entirely incorrect.

Lets address some of the inaccuracies first and see if we can drill down to what the author is driving at.

My understanding (which could be wrong) is that armies in the U.S. civil war were "bloody" in the sense that soldiers did not retreat or were sent directly into fire, until one side was wiped out.

This is not remotely true. The reason why casualties in the Civil War were so high often had little to do with combat, but rather disease. Here's an interesting random fact:

During the Civil War, diarrhea (Greek, meaning “I flow away”) was the most common and deadly disease. More Civil War soldiers died from diarrhea than were killed in battle. About 1 in 40 cases was fatal. Death came from dehydration, exhaustion, or the rupture of the intestinal wall.

Federal soldiers were over twice as likely to die from disease than combat for the Confederates, were just under half as likely to die from disease. (one source quotes 94000 KIA to 164000 of disease).

Nor were battles in the Civil War often decisive, at least in the terms described by the OP. For example, the Battle of Antietam, one of the bloodiest battles of the war, had a Union Army of 75,300 face the Confederate Army of 52,000. Casualties were: Union: 12,400 Confederate: 10,300 1 These are certainly exorbitant casualty rates - in excess of 20% KIA, but certainly not

until one side was wiped out.

If we look at the battle of Gettysburg we see similar casualty rates: Total engaged: South: 75,000 (S) North: 82,289

Casualties North: 23,049 South: 28,063 Total: 51,112

In fact in most wars, battles of annihilation are very uncommon. It's also very rare for commanders to expend the entirety of their armies in combat.

Let's address some of the semantic inaccuracies next.

I'm just curious why the North and South didn't use guerrilla fighting techniques, by which I mean taking cover, spreading out, etc. if these techniques were helpful in the Revolutionary War.

First of all, what you are describing is not guerilla warfare. What you are describing is either modern infantry tactics or skirmishing. This is not irregular warfare necessarily. Wikipedia defines it as:

Guerrilla warfare is a form of irregular warfare in which a small group of combatants such as paramilitary personnel, armed civilians, or irregulars use military tactics including ambushes, sabotage, raids, petty warfare, hit-and-run tactics, and mobility to fight a larger and less-mobile traditional military.

Arda Bilgen of Small Wars Journal offers a lengthier analysis of Mao's elements of irregular warfare

To begin with, Mao puts a great deal of emphasis upon three major elements throughout the book. The asymmetry between a conventional and an unconventional force is indeed one of them. Mao sees this power gap as an opportunity rather than a deficit and maintains that “conditions of terrain, climate, and society in general offers obstacles to [invader’s] progress and may be used to advantage by those who oppose him.

In guerilla warfare, we turn these advantages to the purpose of resisting and defeating the enemy.”[i] In other words, he believes it makes critical sense to ‘provoke and bait’ the enemy to unfamiliar territory and circumstances; dragging the enemy into a murky struggle may even be a precondition for victory. Asymmetry, therefore, is not a source for vulnerability for guerrilla. On the contrary, it is an opportunity to stick to the “conservation of his own strength and destruction of enemy strength.”[ii]

For Mao, the second major element that is of crucial importance is the role of ‘people.’ It is made clear that the guerrilla movement is doomed to fail without the support of locals. In Mao’s words, “because guerrilla warfare basically derives from the masses and is supported by them, it can neither exist nor flourish if it separates itself from their sympathies and cooperation.”[iii]

People are the backbone of a guerrilla movement because they constitute the recruitment pool and play an important role in supply and logistics. Also, the struggle is thought to be in the interest of them. The third element Mao emphasizes is the distinct feature of guerrilla warfare. He argues that “the general features of orthodox hostilities, that is, the war of position and the war of movement, differ fundamentally from guerilla warfare…The enemy’s rear is the guerrilla’s front.”[iv]

In this context, Mao maintains that guerrillas should always be constantly active, mobile and alert no matter how inconvenient the conditions of terrain, weather, or communication lines are. Deception, speed and surprises are all potential game changers. Due to their greater independence, mobility, and maneuver capability compared to centralized forces, guerrillas have the ability to inflict psychological damage in addition to physical damage on the enemy. It might at first sight look like their weakness to operate in small groups that can be wiped out in a matter of minutes. However, since they avoid the static dispositions, they can easily and secretly move into the vulnerable rear of the enemy.[v] Mobility, therefore, is a sine qua non principle along with the asymmetry and people, from Mao’s perspective.

Comparing Mao and Kilcullen - Small Wars Journal 17/11/11 - Arda Bilgen

Guevara describes it as

"used by the side which is supported by a majority but which possesses a much smaller number of arms for use in defense against oppression".

The two actors in the Civil War do not fit this bill. Whilst the Confederacy was much, much weaker than the North, they were both near peer state level adversaries. Not only this, but both sides engaged in conventional warfare, seeking to capture and hold territory.

We also need to examine the end-states, or victory conditions for either side. For the South, all that was required for victory was to defeat Union aggression, whereas the North had to effect a reconquest of the South in order to achieve victory. Strategic guerilla warfare (a le Vietnam or the Revolutionary War) was not an option for either actor as it did not help fulfill their victory conditions.

Let's correct something else in another answer

What did Stonewall Jackson do in the Shenandoah Valley?

The Shenandoah Campaign (Bull Run) was unequivocally not a guerilla campaign. It could possibly be described as a 'deep raid', but was ultimately carried out by regular forces in a conventional campaign using maneuver tactics.

That said, there were in fact guerilla actions carried out by partisans on both sides. However, these campaigns were not strategic in nature, and were devolved local actions that were usually detached from the conventional command structure.

Wikipedia describes them as:

In general during the Civil War, this type of irregular warfare was conducted in the hinterland of the Border States (Missouri, Arkansas, Tennessee, Kentucky, and northwestern Virginia / West Virginia). It was marked by a vicious neighbor-against-neighbor quality as other grudges got settled. It was frequent for residents of one part of a single county to take up arms against their counterparts in the rest of the vicinity. Bushwhacking, murder, assault, and terrorism were characteristics of this kind of fighting. Few participants wore uniforms or were formally mustered into the actual armies. In many cases, it was civilian against civilian, or civilian against opposing enemy troops. Wikpedia - Guerilla Warfare during teh Civil War

The author is conflating modern infantry tactics with guerilla warfare. His initial question: "Why didn't the actors in the Civil War conduct irregular warfare?" can be answered with: "well they kind of did" - although there were varying level of attachment to regular forces.https://en.wikipedia.org/wiki/Trans-Mississippi_Theater_of_the_American_Civil_War

The reasons for the high casualties were evolving battlefield technology, poor command and control of large armies which American officers had no experience with, and disease. Contact with the enemy was common and bloody but rarely decisive. By the time the Confederacy seriously examined the prospect of irregular warfare on a strategic scale, the war was already lost, and they quite wisely decided to throw in the towel. However, local partisan actions did occur but was as often civilians settling scores with each other or paramilitaries operating behind enemy lines, without formal oversight from the chain of command.

EDIT/part 2

So I think that's only the first part of what the author was really thinking. It was sort of nagging at me over the past couple of days.

So what the author I suppose is really talking about is actually why (if it was) fought with Napoleonic style tactics rather than more modern infantry tactics as we saw evolve over the next century.

So to re-frame the question:

What impact did Civil War Tactics have on casualty rates, and how does this compare to similar conflicts? Were nhe higher casualties rates were a result of disease.

Some commenters and answers were also quite correct in bringing up the smooth-bore rifle, and the advent of rifling and the implications this had for the conduct of warfare.

I also believe that we need to place 'modern' infantry tactics in context as the move from formations of infantry on the battlefield to the evolution of small unit tactics.

So to start with Wikipedia describes the state of tactics at the start of the war.

Traditionally, historians have stated that many generals, particularly early in the war, preferred to use Napoleonic tactics, despite the increased killing power of period weaponry. They marched their men out in tightly closed formations, often with soldiers elbow-to-elbow in double-rank battle lines, usually in brigade (by mid-war numbering about 2,500–3,000 infantrymen) or division (by mid-war numbering about 6,000–10,000 infantrymen) strength. The

This had the consequence on the battlefield that:

This large mass presented an easy target for defenders, who could easily fire several volleys before his enemy would be close enough for hand-to-hand combat. The idea was to close on the enemy's position with this mass of soldiers and charge them with the bayonet, convincing the enemy to leave their position or be killed. At times, these soon-to-be outdated tactics contributed to high casualty lists.

We know that at that outbreak of the war the Union Army was sing the 'Hardee handbook' which still called for soldiers to march shoulder to shoulder. The generals expectations were something akin to the Napoleonic wars. The text of which can be found here Hardee's

John Watts de Peyster advocated making the skirmish line the new line of battle during the Civil War. By the end of the century, fighting in formation had fallen out of vogue and essentially all infantry became skirmishers.

His treatise New American Tactics was a series of articles published in The Army and Navy Journal that advocated making the skirmish line the new line of battle, which was considered revolutionary at the time.[10] These contributions were translated and copied into foreign military journals, including Correard's renowned Biographie des célébrités militaires des armées de terre et de mer. Such tactics were put into practice by generals including John Buford and were later adopted worldwide.[10]

Several innovations were important to the changing conditions on teh battlefield which played a part. We need to look at the evolution of warfare from around the period to track how these changes affected tactics.

For example at Antietam, soldiers were reported to take cover when firing on the enemy. House, stonewalls and even rocks were used as cover by troops rather than fighting in lines.

'Hardee formations' were used for traveling on the battlefield, initially firing by volley from the line. However as the war dragged on soldiers began hiding behind fortifications whenever they could. Once in battle soldiers would take whatever they could find for cover. These formations were still necessary for coordinating large bodies of troops. Command and control on the battlefield was limited to bugle calls an shouting.

The Minie Ball was a major innovation in musketry - allowing a much greater accuracy and rate of fire. The innovation itself drove wider adoption of the rifle, a long reload times no longer were as much of a concern.

Wikipedia describes the physical charac3ersistics of the Minie Ball:

a conical bullet (known as a Minié ball) with a hollow skirt at the base of the bullet. When fired, the skirt would expand from the pressure of the exploding charge and grip the rifling as the round was fired. The better seal gave more power, as less gas escaped past the bullet, which combined with the fact that for the same bore (caliber) diameter a long bullet was heavier than a round ball.

The Minié system allowed conical bullets to be loaded into rifles just as quickly as round balls in smooth bores, which allowed rifle muskets to replace muskets on the battlefield.

The invention of the minie balls in the 1840s solved the slow loading problem, and in the 1850s and 1860s rifles quickly replaced muskets on the battlefield.

The extra grip also spun the bullet more consistently, which increased the range from about 50 yards for a smooth bore musket to about 300 yards for a rifle using the Minié system. The expanding skirt of the Minié ball also solved the problem that earlier tight fitting bullets were difficult to load as black powder residue fouled the inside of the barrel.

There are alternative viewpoints on the efficacy of the rifle in driving tactical innovation. As quoted below, Guelzo believes that the rifle did not maintain a sufficient casualty to to shot ratio to have sufficiently.,

However, historians such as Allen C. Guelzo reject this traditional criticism of Civil War infantry tactics. Casualty estimates compared with expended ammunition from battles indicate 1 casualty for every 250–300 shots discharged, not a dramatic improvement over Napoleonic casualty rates. No contemporary accounts indicate that engagement ranges with substantial casualties between infantry occurred at ranges beyond Napoleonic engagement ranges.

The historian claims that until the advent of smokeless powder, generals were not able to take advantage of the full potential of rifles. Wikipedia describes his conclusions:

Thus Guelzo doubts that contemporary military leaders blatantly ignored technological advances. Rather, Guelzo argued that in actual battlefield conditions, until the development of smokeless powder, the benefits of rifling were largely nullified. Therefore, generals did not alter their tactics not due to ignorance, but because the battlefield had not changed substantially from the Napoleonic era

Others argue that the rifle madeimportant contributions, such as. Wall of Fire - Evolution of Civil War Tactics-sic Major Richard E. Kerr In his paper " see above" - Kerr argues the rifle definitely had a role, and gives us a detailed account of how in the Maryland campaign this had dramatic consequences on tactics.

Major Kerr goes to great detail on this very topic in his paper Wall of Fire, examining the use of the rifle on infantry tactics in the civil war. Kerr examines a number of factors, and describes the debate between whether the rifle was the driver of the new tactics of fortification, or whether the new tactics came before the widespread adoption of the rifle.

He states that at Antietam :

Based on comments from the Operational Records, units often ran out of ammunition, they used Hardee's drills to get around the battlefield, but the soldiers fought from covered and concealed positions whenever possible. Fighting in the open, standing up, resulted in exceptional casualties.

So around 1862 we see unit tactics under fire evolving and commanders were moving away from the Napoleonic formation warfare as prescribed by Hardee, and towards fighting from cover ; the use of fortifications also became common place. Rifles still had a longer reloading time and naturally the soldiers felt more comfortable behind some kind of shelter from the now more discriminate rifle fire.

One of the primary innovations of civil war tactics during the war was the widespread use of fortifications to contain the enemy armies. These preceded the use the of trench war, although the Americans had yet to fully capitalise on or develop the automatic machine gun.

To revist the central question, did new infantry tactics cause high casualties rates> Not so much, the rifle had an impact on the way the war was conducted but some data suggests it wasn't considerably more lethal than the smoothbore musket until the advent of smokeless powder. Prior to this large units with rifles would obscure the battlefield over time with thick white smoke, negating its range benefits.

The minnie ball itself was also an important innovation. It seems that there were a cluster of innovations surrounding small-arms at this time that were all important contributors to the evolution of tactics.

Effects on military thought

There is a correlation between the advent of the rifle itself and the rise of the skirmisher. As mentioned, the rebels from the Crown used skirmisher tactics made possible by improvements in musketry to good effect versus the British in the Revolutionary War.

There was an evolution from the Revolutionary and the adoption of the rifle where American militia engaged in skirmishing tactics, rather than pitched battle; to skirmishers being an integral parts of all European armies in the Napoleonic Wars.

Skirmishers were central to fighting in the Napoleonic Wars as a way ti disrupt the enemy line and as Kerr demonstrates, fighting in lines went out of fashion at least in the civil war by 1862, He describes a kind of hybrid between Hardee's drills and more what John de Peyster envisioned. Quick evolution of skirmishing

We see this trend continue along with improvements in the Franco-Prussian War.

The German casualties were relatively high due to the advance and the effectiveness of the Chassepot rifle. They were quite startled in the morning when they had found out that their efforts were not in vain—Frossard had abandoned his position on the heights.[47]

The French breech-loading Chassepot rifle demonstrates as the rifle improved so did its impact on the tactics of armies on the day.

German tactics emphasised encirclement battles like Cannae and using artillery offensively whenever possible. Rather than advancing in a column or line formation, Prussian infantry moved in small groups that were harder to target by artillery or French defensive fire.[22] The sheer number of soldiers available made encirclement en masse and destruction of French formations relatively easy.[23]

So what we can conclude from our obseva of the Franco Prussian War - is that what took a greater role was the coordination of large armies in the creation of a General-Staff, as well as the use of both cavalry and artillery.

For the Americans drills were still probably the only way the generals on both sides could keep any semblance of control of the armies overall. Both sides were hampered by terrible or insubordinate unit commanders. Even when generals could make changes to strategy, he depended on his unit commanders to carry it out. The war's decisive movement often hinged on the lack or laxity of a subordinate.

Conclusion:

There was a distinct evolution during the war, consistent with benefits else derived form the use of the rifle, of infantry tactics. The rifle had a growing impact as other innovation improved its effective range on the battlefield by reducing smoke and better cartridges.

The rifle itself obviously had a real impact on the conduct of warfare over the course of the war.

However it wasn't the only driver of change in Civil War tactics. The existence of railways meant that armies could be moved greater distances with ease. Armies could be raised trained and equipped faster than before.

The increasing accuracy and proliferation of artillery meant that line formations wer no longer tenable. Units spears out to avoid the shellfire. The civil war really marked a transition point to Industrial warfare.

Commanders moved away from formations to favouring the defense and open infantry tactics. We see a lot of precursors to to the same technical challenges of using artillery to soften up prepared positions to trench warfare in WW1. The use of artillery also drove the dispersal of unit formations; as field artillery accuracy and rate of fire, it was simply too dangerous to form up in the open.

Both parties were cognizant of a rifle shortage early in the war but took to importing more rifles from Europe until domestic production took over the shortfall as happened in the North. The ability to produce more weapons than the south was one of the deciding factors in the war.

Rifles became much more prevalent as these changes from Hardee to more modern warfare (de Peyster) as each side had more to experiment too much. We see a clear trend as rifles become ubiquitous and powerful, we see the breakdown of traditional 'Hardee' combat..

The Prussians split their their infantry early in the F-P War, but nonetheless experienced heavy casualties from the entrenched French.As the rifle evolved infantry tactics evolved nations eliminated line infantry altogether.

As for why the war was so bloody? Well I think overall the general competence and inability to adopt to change methods of war in the first half of the war. Generals and commanders were unable to handle their formations or follow basic instructions. In the later half of the war, the attrition tactics adopted by Grant increased the focus on inflicting casualties on the CSA armies to allow the Northern industrial to over take the South. The battle of the Wilderness is a good example of this strategy at play.

There are more case studies but I think I'll publish this as draft for now

t 1,030,000 casualties (3 percent of the population), including about 620,000 soldier deaths—two-thirds by disease, and 50,000 civilians

sources

https://en.wikipedia.org/wiki/Infantry_in_the_American_Civil_War

This random video offers a concise explanation as well. http://www.civilwar.org/education/in4/infantry-tactics.html https://en.wikipedia.org/wiki/Siege_of_Petersburg https://en.wikipedia.org/wiki/Franco-Prussian_War