What the Pinkerton estimates were of, an answer.

Although he missed the point, the information needed to work out what the parameter Pinkerton was reporting (and McClellan using) is in Fishel's Secret War for the Union.

Pinkerton obtained the roster strengths, that is the "aggregtate present and absent" and applied a correction factor to take out the sick. He meant to use 15%, but apparently his computer used 1/15th instead, thus overstating the enemy strength by about 10%.

Thus is explained why, by inspection, Pinkerton's numbers usually seem in good aggreement with the aggregate present and absent, they were the basis of his reports, and he is not doing his maths properly. It does not explain some of the figures his interogators were producing.

The 68 Pounder 95 cwt

For years I've taken Lambert's Warrior at its word, the initial velocity of a 68 pounder was ca. 1,580 fps. Now, reading contemporary works from the 1860's I find that this is not the velocity with a "far" or "battering" 16 lb charge, but seems to be the velocity with the 12 lb "service" charge.

Reading Holley's Treatise on Ordnance and Armour I find that with the 16 lb charge the gun developed a muzzle velocity of over 2,040 fps. This goes an awfully long way to explain why the Royal Navy kept this gun as an anti-armour piece into the mid-1860's. For comparison, with a 60 lb charge (of Mammoth) and a 451 lb ball a 15" Rodman only developed around 1,200 fps.

The key parameter to consider is the powder charge: shot weight ratio. In the 15" even with 60 lbs of powder the powder charge is only 13% the shot weight. In the 68 pdr it is around 25%. The slow burning Mammoth is less efficient, and the shorter barrel (in calibres) means the burning charge has less time to accelerate the projectile.

Simply correcting myself after years of using the 1,580 fps figure....

R.I.P. Paddy Griffith

Paddy Griffith passed away at his home in Manchester on the 24th June. He will be sorely missed. His contribution to the study of the American Civil War was outstanding.

R.I.P. Dr. Paddy Griffith (1947-2010)

The Royal Navy Force Designated for America, 1862

This is a bit of a datadump, it's information accumulated that I've posted on line elsewhere, but ought to here.

Using the defence plans for Canada, and the Hydrographer's report to Adm. Milne we can estimate the British Royal Navy force that they planned to use in the event of war with the United States.

WO33/11 gives the planning figures for the defence of Canada:

At Quebec: 2x line of battle and 1x ironclad battery

Operating between Quebec and Montreal: 2x ironclad battery, 2x corvettes (noting a maximum draught of 18 ft), 2 dispatch vessels and 7 gunboats

On Lake St. Francis: 4x gunboats

On Lake Ontario: 3x ironclad battery, 4x dispatch vessels, 16 gunboats

On Lake Erie: 3x ironclad Battery, 20x gunboats

On the Richelieu River: 6 gunboats

Total for the inland seas of Canada: 2 line-of-battle, 9 ironclad batteries, 2 corvettes, 6 dispatch vessels, 53 gunboats = 72 vessels

Three of the nine ironclads were to come from the existing Crimean War ironclads, probably as only one (HMS Aetna) can actually transit onto Lake Ontario (she just squeezes into the locks with 6 inches to spare at the beam). None of the batteries have engines strong enough the run the rapids. Six of these ironclads are available for service (Meteor is already uncased and awaiting wrecking, Trusty has been converted into an experimental turret vessel and is likely too unstable to risk at sea). The cost of these six new ironclads was set at £300,000 for all six, slightly cheaper than the ironclads of 1854-5. Build time was to be 90 days.

The force recommended by Captain Washington to blockade the Unites States was:

Penobscot Bay: 2x sloops, 2x gunboats

Kennebec River: 1x sloop, 2x gunboats

Portland: 1x frigate, 2x sloops, 2x gunboats

Portsmouth, NH: 2x sloops (and notes the defences mean a mortar vessel can range on the navy yard without any return fire)

Salem and Marblehead: 1x sloop

Boston: 1x line of battle, 2x frigates, 2x sloops, 2x gunboats

Nantucket Island: 1x frigate

Narrgansett Bay: 3x sloops, 3x gunboat

Long Island Sound: 1x line of battle, 1x frigate, 2x sloops, 2x gunboats

New York Harbor (South Entrance): 2x line of battle, 2x frigates, 2x sloops, 2x gunboats (much ink is spilled over how to attack New York)

Delaware River: 1x line of battle, 1x frigate or sloop, 2x gunboats (4 if possible) (much ink is spilt noting that a gunboat flotilla could penetrate up the Delaware as far as Trenton, NJ, and that a gunboat force on the river could destroy the Dupont powder mills, smash Philadelphia and other such nastiness)

Chesapeake Bay: 2x line of battle, 2x frigates, 6x sloops, 6x gunboats

Port Royal, SC: 1x frigate, 1x sloop

Total blockade: 7x line of battle, 12x frigates, 25 sloops, 23x gunboats = 67 vessels

This didn't include a cruising force of 25 vessels of the West India Squadron. Nor does it include Milne's planned particular service squadron, which was to include Warrior, Black Prince, Defence and some other ironclads (probably the available three), plus some line of battle and a large gunboat force. This last force was the most worrying, Milne planned on reducing coastal fortifications (starting with Fort Monroe and moving into the Chesapeake) and sending gunboats up the navigable rivers to destroy everything that was shellable. Unfortunately for the US that is quite a lot of war industries.

Livermore, numbers, black confederates and trying to arrive at a true "effective strength" value: part 1

One century and one decade ago Thomas Livermore published "Numbers and Losses in the Civil War in America 1861-5". It is out of copyright and freely distributed here. In it he made the first serious stab at trying to level the playing field and use directly comparible numbers. To wit:

The Records, apparently following the reports and returns of the commanders, give the numbers in the different campaigns and battles variously as “present for duty, “present for duty equipped”, or “effective. Sometimes the last-named class excludes on both sides the non-combatants, and on the Confederate side the officers and even artillery and cavalry ; and, in the effort to number only the men bearing muskets in the firing-line, the stragglers, even those who have left the ranks on the field of battle, are sometimes excluded in reports of battles.

This practice of counting as effective in the infantry only the men bearing muskets in the firing-line is of great value for informing commanders what weight of fire they can deliver, and the state of discipline in the ranks; but it cannot be followed in ascertaining numbers for comparison between the two sides in the civil war, or between the numbers in battles of that war and other wars, because the published accounts of the Union army, and of armies in other wars, do not usually state numbers on this basis. Officers, artillery, and cavalry are assuredly essential parts of the effective force of an army, and the efficiency of an army is certainly to be gauged quite as well by the number of combatants who fail to join in battle as by the valor of those who come into the firing-line. On the other hand, it is reasonable to exclude non-combatants from those counted as effective for battle. In both the Union and Confederate armies, the members of the regimental, medical, and quartermaster’s departments, and the musicians, were non-combatants, and few of them were ever present in the firing-line, for even the drummers and fifers were usually employed in caring for the wounded; and these non-combatants, although essential to successful campaigns, cannot be said to have had any influence in the decision of battles in the civil war.

...

[T]here is no reason for concluding that [the number of non-combabtants] was ever less than seven per cent, of the total “present for duty” in the infantry and artillery. Repeated instances are found in the Records where the numbers given as “effective” in infantry corps or divisions are from 89 to 93 per cent, of the number present for duty, while in the cavalry the per cent, is often from 83 to 86. The lower per cents, may be accounted for by the deduction of men without arms in the infantry, and of men without mounts in the cavalry. It is apparent that the commanders of corps in the Union army did not all follow the same classification in counting the numbers “present for duty equipped” or “effective” for in some returns these numbers are the same as, or under one per cent, less than, the number “present for duty” and sometimes they are stated as even greater.

Although the Confederate returns bear evidence of having computed the “Effectives” more consistently, yet it is apparent in some cases that a sufficient deduction is not made for the non-combatants. In view of these facts, the writer, adopting the number of effectives given in the Official Records in the few cases where they seem to* be properly determined, or where the number present for duty is not given, has in other cases computed the number of effectives in the infantry and artillery at 93 per cent., and in the cavalry at 85 per cent., of the number present for duty. In cases where the number of effectives given in the Confederate returns is used, an addition is made for officers if they appear not to have been included. In this connection it is to be observed that in the Union armies the number of officers ran from 4 to 7 per cent, of the total present for duty, while in the Confederate armies it ran from 6 to 11 per cent.

- Livermore, Thomas; Numbers and Losses in the Civil War in America 1861-5, pgs66-70

Livermore essentially used the relationship between the Confederate "Present for Duty" and "Effective" figure and applied it to the Union. He also notes the Confederates had a larger percentage of officers overall. This is telling, both sides recruited officers at the same rate (34 officers per infantry regiment). Either the Confederate army atrophied more by non-combat losses or we have two different counting methods for "Present for Duty".

In fact this is true. Some Confederate returns have an additional column between "Present for Duty" and "Aggregate Present" labelled "Total Present". This appears to correspond with adding back in those "duty men" who were not available for line of battle.

Also, the Confederate "effective" column corresponds with the "Present for Duty - Enlisted" in those cases I've checked.

Making matters more complicated, neither side reports civilians attached to the army. In the Confederate Army this included their "negros", both free and slave. These were not enlisted and do not show up on the returns for the armies*. Whilst some white Confederates did serve as teamsters they were few and rapidly replaced by the non-whites to free them for the firing line. However in the Federal Army a large number of men had to be detached for this work (and they were detached for six months at a time, and were borne as "present for duty" on their parent registers rolls irrespective of the fact they were on regimental parades).

These facts add up to the fact that Livermore didn't get the factors right. One of his fundamental premises, that "present for duty" meant the same in both armies, is false. In part 2 I shall look at other estimates by those that took part in the war, and show the impact on the force balance of various civil war battles.

* Ingalls (Quartermaster, Federal Army of the Potomac) acquired 2,000 negro workers for his quartermasters corps on the Peninsula and took them with him. They don't show up on Federal states as far as I can tell.

McClellan's numbers - which ones?

Anyone who was delved into the morass of civil war statistics is well aware that we have various different numbers we can use for measuring armies with various different meanings. The two extreme values are combat effectives (the number on the battleline only) and aggregate present and absent (the total number of names enlisted, including those physically not with the army).

Now, when McClellan (or any other officer) makes an estimate of enemy strength, which one of these numbers is he using? This is important as if he was using the highest categories of enemy strength he's actually correct in his "phantasmal" numbers. If he is using the lowest he is wildly overestimating. Unfortunately he never actually says.

We do know that the numbers he adopted for the force in front of him at Yorktown after the siege were from a captured ration roll, showing 119,000 men. This is an expression of the aggregate present and absent. After this he consistantly uses the figure of 100-120,000 until not long before the Seven Days. In this there is absolutely nothing wrong, it is a very reasonable deduction (approximately this figure appears in Livermore). Of course, viewed from the angle of combat effectives there seems to be a lot wrong. The question is what did McClellan think these figures were, effectives, present or aggregate?

Here we don't know, and this is the crux of the problem. The best idea in my head is to keep an open mind and look at how he behaved, the clues are likely there....

Short Review: Controversies and Commanders by Stephen Sears

Happened to read this book yesterday, and it's a mixed bag.

Firstly we have several more chapters on why McClellan and friends were so bad. These are essentially a continuation of his previous arguments.

However, we then have two very good chapters. "The revolt of the generals" covers the dysfunction that effected the Army of the Potomac's command structure after McClellan was removed, culminating in Burnside trying to dismiss almost the whole of the top level command before being relieved of duty. It of course has the typical swipes at McClellan one would expect from Sears; "McClellan had managed (at least to the satisfaction of the officer corps) to disguise the reverses of the Seven Days and shift responsibility and lay the blame on shoulders other than his own.". As if the entire officer corps of the Army of the Potomac were a bunch of shills to be conned.... This chapter should be read with the next; "In defence of Fighting Joe", a well written attempt to vindicate Hooker. Only putting these two together can we understand the authors overall intent, to build a picture in which Hooker's failure is the fault of others. Even the blurb on the back spells out that Hooker's firing was not justified in Sears' eyes.

Much of the rest of the book is taken up with examining other Generals and a pattern emerges, the Republican Generals are lauded and defended whilst the Democrat Generals are derided and subject to character assassination. In this I've come to the conclusion that Sears has a "Radical Republican" agenda, which makes his works much easier to understand.

Beauregard in the Seven Days?

One thing about the Seven Days Battles is the question of why McClellan's intelligence apparatus suggested that Beauregard was at Richmond. In point of fact he was at Richmond, after having been fired from command of Department No. 2. The northern papers had reported it, such as this article in the New York Times dated 24th June 1862. Later they report on the 29th that his army is following, the day before that they reported a considerable portion of it had arrived already. They'd reported that Beauregard may move there a month earlier.

It appears that the Union papers (and hence intelligence apparatus) had detected the start of Bragg's change of base from Tupelo to Chattanooga, but combined with the appearance of Beauregard in Richmond had put two and two together and made five. It looked like a detachment of Beauregard's army was going to Richmond.

Now, McClellan's apparatus apparently detected the movement of the force under Holmes from the Department of North Carolina and Southern Virginia. Under questioning prisoners from Holmes claimed to be part of Beauregard's Army (matbe Pinkerton's interrogators asked leading questions....). They too put two and two together and made five. The result was that McClellan was getting intelligence from several directions, although he does not necessarily believe it. His communique to Edwin Stanton states he would "have to contend with vastly superior odds if this were true." (emphasis mine). Of course there is sufficient weight of evidence to give some credence to this at the time.

McClellan was wrong about Beauregard's army being in Richmond. However, there was sufficient evidence to that effect that pointed to it that the conclusion was reasonable given what was known at the time.

The discrepancy between "global returns" and real life

When considering the overall strength of the Union army tables like this are usually brought up:



This table, from the OR (OR 3, Vol 2, 957) shows an aggregate strength of the Union Army as 664,163. This is quite a force. Compare with the number of regiments published a month earlier:




Now, lets consider the average strength of a volunteer infantry regiment (counting an independent company as 1/10th of a regiment). There are 816.7 Regiments with an aggregate PFD of 573,420 and an aggregate absent, sick or wounded of 107,109. That means the average Union regiment just before the Battle of Fredericksburg was 702 PFD and 131 absent, sick or wounded (833 aggregate present and absent).

Doing the same for the cavalry yields 89.7 regiments with 700 PFD and 133 absent, sick and wounded (833 aggregate present and absent). The artillery has 28 regiments (of 12 companies) with 958 PFD and 176 absent, sick or wounded (1,134 per regiment).

Now, have you ever read of 700 man regiments in the field? They're incredibly rare.

Burnside's Army of the Potomac at Fredericksburg has 265.5 infantry regiments (including a few regular units not in the volunteer count above), in round figures a third of the Union infantry. They also have 18.9 cavalry regiments and 70 companies of artillery. If they were "average" as above they'd have:

186,231 infantry PFD
13,230 cavalry PFD
5,588 artillery PFD
= 205,049 men PFD

In fact (using his 10th December 1862 return (ref))his three active "Grand Divisions" used in the count above only sum to 118,952 PFD and only 103,190 infantry PFDE (adding in the Vol engr bde it becomes 104,695). Using the latter figure the average infantry regiment in Burnside's army (accounting for ca. a third of the total infantry) is 394 (56% of the count above). The PFDE (all arms) of the three Grand Divisions is 114,612 and the aggregate present 138,927, or 17.5% of the aggregate present are not PFDE, this is the sick list (at ca. 1 in 6 is absolutely typical of an army in the field). The PFD or PFDE must be reduced by taking out the daily and special duty men to arrive at an effective combatant strength. We can estimate the Grand Divisions had 90,000 with the combat units and around 77,000 effective infantry (about 71,000 enlisted effectives, the normal CS measure). Thus the musket strength of an average infantry regiment in Burnside's army is now down to around 266 muskets.

If this was typical of the entire Union Army then not 220,000 muskets would be in the field. It is this thinking that has me doubting that the Union ever had 600,000 effectives in the field. I tend to regard Union strength as around 300,000, maybe 350,000 depending on exactly when we measure.

Numbers in Stephen Sears' Books, part 1: The Landscape Turned Red

In a short series of posts I will deal with the strength figures in the books of the author Stephen Sears, starting with his book on Antietam "The Landscape Turned Red", principly because it is the easiest.

The first strength figure is on page 102 and deals with the total strength of the Army of the Potomac on 7th September. It lists 85,000 "under arms" (i.e. effectives) in McClellan's Army and 72,500 left to defend Washington. Sears states that because of serious straggling ans sickness en route to Frederick McClellan was setting forth with nearly a 2:1 advantage, 3:1 if he could call in reserves from Washington.

The figures are from (a) Palfrey's the Antietam and Fredericksburg pg 7 and (b) OR19(2) 264-5. Although the latter carries the caveat in the original (not reproduced in Sears) "There is the old exaggeration in these figures, due to failing to distingish between for duty and extra or daily duty.". The former 85,000 was obtained by Palfrey taking the 20th September return of 89,452 (this figure being the aggregate present), deducting the strength on that date of Porters Corps (19,477) and adding the casualties sustained of 14,794 yielding, in round figures 85,000. Although represented by Sears as an effective strength, this appears to be an aggregate present strength (or at least PFD). Lee on this date had around 75,000 "for duty" and a larger number "aggregate present". Thus rather than 2:1 or even 3:1 superiority, McClellan's army had rough numerical equality.

On page 117 Sears adopts the value in McClellan's report of 87,000, noting that this is "almost exactly double". It is roughly parity.

On page 163 Sears states that "60,000 fighting men" (i.e. effectives, in fact this figure would fit the PFD of the force present on the field on dawn of the 17th) were with McClellan at Antietam on dawn of the 16th September, giving him a 4:1 superiority in numbers (then quips about McClellan's "phantom calculation). In fact McClellan had 48,000 effectives strung out, still on line of march (Harsh, Taken at the Flood, p330). Only 2 of McClellan's Divisions were on the field, Richardson's (lead division of Sumner's wing) and Sykes' (lead division of Burnside's wing), with maybe 6,000 effectives between them. Rather than outnumbering Lee by 4:1 as Sears suggests, McClellan's forces on the field at dawn were outnumbered 3:1, although this quickly changed during the day as the columns came off their roads and ployed into position. There was no massive superiority in numbers that McClellan missed (and in fact McClellan endeavoured to attack as soon as he had 3 Corps up but the movements of his subordinates were too slow).

On pages 173-4 Sears has his last words on strength, giving a statement of the balance of strength. He states that "by roster counts" McClellan had 75,000 of "all arms and services", plus another 19,000 in the Loudon Valley under Franklin. He also gives the whole armies effective strength at 71,500 (although not explicit, running through the attached footnote and repeating his maths shows that he has included both the force in the Loudon valley and Humphrey's division in this figure, which is based on Carman's figures with an attempt to add the forces Carman didn't count in them. There is no attempt to fix, i.e. downrate to "effectives", those figures given by Carman as PFD or even aggregate present). Lee has "fewer than 26,500" including his artillery and cavalry after Jackson and Walker arrive (i.e. McLaws, Anderson and AP Hill aren't up yet, as the text makes explicit, but no numbers are given for them in the book, in a footnote Sears quotes "less than 40,000" and "not 35,000" excluding cavalry).

It is clear Sears understands the difference between effectives and present (since it is explicit in his main source, Carman), but seems to adopt the maximum possible value by including forces not on the field on the 17th (covering this as forces under McClellan's command), whilst adopting the lowest possible effective value for the Confederates (for example, following Carman only half of AP Hill's division is counted). McClellan certainly did have superior numbers during the battle, but a careful examination of Carman places this figure between 5:4 and 3:2, rather than 2:1 used here.

Overall, although the figures chosen are those that make Sears' case look best, by using Carman Sears has not majorly run off track (although his figures for the morning of the 16th are very wrong, they're not referenced and so were probably taken from the known strengths at the end of that day rather than the begining). The most serious mistake is including forces that didn't arrive in time to participate in the battle.

Next we shall look at his Richmond Campaign, and see his figures without the crutch of Carman. Then I'll read his Chancellorsville and Gettysburg books.

Yorktown: Some Context

On the 22nd April 1862 Joe Johnston famously wrote "No-one but McClellan could have hesitated to attack." (ref). This quote is widely used in many general history books but as far as I can tell no-one has ever looked at what Johnston and McClellan actually thought the force balance was.

The Confederates believed McClellan had 200,000 men(ref), whereas when he contacted the Confederate works he had 45,000 PFD (ca. 30,000 effective infantry, plus supporting arms).

McClellan believed that the Confederate position was 18,000 or 20,000 strong, reinforced to 30,000 on the 7th (ref, and next page) and that his total force, including that not up yet was 68,000 PFD.

Earl J. Hess in his Field Armies and Fortifications of the Civil War, the Eastern Campaigns 1861-4 calls the Yorktown entrenchments "one of the strongest defensive positions of the war." (ref). Thus the combat power of Magruders, later Johnstons force is magnified many times.

Johnston's comment of the 22nd April is based upon the false notion that McClellan had over 10 to 1 supremacy in numbers when he contacted the Warwick Line. In fact it was closer to 3:2. When McClellan's entire command was up it numbered roughly 72,000 present (plus another division afloat after the 16th April), and thus maybe 60,000 effectives of all arms. Johnston had 55,000 effectives of all arms in the entrenchments and in reserve at Williamsburg. Thus there is rough numerical parity. To be fair, we should point out that towards the end McClellan received intelligence that Lee was reinforcing Johnston to 80,000 (ref), although it should be pointed out that this is an entirely reasonable "aggregate present" figure, and that according to Livermore the aggregate present and absent of Johnston's command is around 125,000 (Numbers and Losses, p43-4).

There certainly may have been an opportunity for assault. Beattie's coverage of events here is excellent (Army of the Potomac vol. 3, chapter 16). McClellan's army stepped off on the 5th April with orders to roll over the Yorktown position, but rain slowed the march, the rivers swelled and when they arrived the position was completely dominated by Confederate artillery. The Federals tried to assault twice anyway (although only reconnaisances in force, had either been successful the whole line was in place to attack), and McClellan didn't decide on a siege until 17th April (Beattie, chapter 21). It took two weeks to build irresistable siegeworks and the Confederates didn't wait to be on the receiving end of the bombardment.

In conclusion there is no reason to believe that McClellan was in the dark about what faced him, he just believed (IMHO, correctly) that the position was too strong, and tested this by several probes before settling down to blast it out. When half a century later generals ordered assaults on prepared positions with large fields of fire for crew served weapons we call them butchers and "donkeys", yet we deride a general who had learnt this lesson (from viewing the siege of Sebastapol) and declined the casual butchery in favour of actually winning.

McClellan's View from the Pry House

You find some odd things on youtube: