Unless I missed them, it looks like the 3rd SC Battalion, Philips’ Legion, and the 5th FL are not recorded in the OR (Official Records, Series I, Volume XIX, Part 1, pp. 803-10) as having been part of the AoNV during the Maryland Campaign.
Interesting. Doubly interesting because the 5th Florida had two commanding officers (Col John C. Hately and Ltc Thomas B. Lamar) wounded at Antietam, and because they were part of Pryor's brigade, joining Anderson's division from Wilcox's division during September. Also because they're recorded as fighting in the cornfield.
The 3d SC Battalion was part of Drayton's brigade as far back as Second Manassas, and lost 132 men of 250 engaged at South Mountain, losing LtC James (KIA), Major Rice (WIA) and Captain Daniel Miller (MIA) at that battle, before fighting at Antietam.
Philips' Legion was also part of Drayton's Brigade and fought at Fox's Gap, losing 31 KIA, 39 WIA and 41 MIA. It also lost LtC Cook, Captains Daniel and Hamilton, Lt. Bowie and the chaplain WIA, Major Barclay MWIA and Captain Johnson MWIA, as well as three lieutenants killed and two captured; the senior officer at that point was Lieutenant Price of E company.
Those formations lost pretty heavily during the Maryland campaign. (Information from the Civil War in the East site.)
The OR has the total confederate dead/wounded in the Maryland Campaign at 10,291.
Does that include the cavalry, out of interest? I believe the cavalry filed separate returns, as they're not listed at all in the entire set.
As I suspected, that number is significantly lower than the commonly accepted total of 11,730 confederate dead/wounded. It’s a difference of 1,439. That’s where the missing casualties are, of course.
So that 1,439 includes the cavalry casualties,
all the MIA and the casualties from the eighteen missing regiments? Or does it not include the MIA?
Regardless, here is a source for captured Confedederate wounded:
OR S1 V19 P1 Pg 111:
"In addition to our own wounded, we had upon our hands from the battles of South Mountain, Crampton's Gap, and Antietam in all about 2,500 Confederate wounded".
That's MWIA. It is greater by itself than the normal statements of captured Confederate troops.
Thus if we assume that all the missing regiments and all the cavalry casualties, but
not the MIA, are accounted for in the 11,730 number, our lower bound for Confederate losses in the campaign is 14,230. Any captured unwounded are in addition to that, as are any KIA who were "MIA" in that their death was not properly recorded by the Confederates as KIA.
Since there were definitely several thousand (unwounded) Confederate prisoners at Fort Delaware in late September, and since there was definitely a big exchange where about 5,100 troops were able to "be made immediately available for the field" as of the 15th September, then it seems that there were indeed a few thousand captured unwounded... or, if not, the Union held onto those prisoners for months despite having means, motive and clear opportunity to exchange them. (No significant captures of Confederate troops took place in August, or in July aside from possibly Malvern Hill, while two big captures of Union troops had taken place at Richmond KY and Harpers Ferry in quick succession. It beggars belief that the Union would have a pool of well over 2,000 prisoners retained at Fort Delaware for months and yet fail to use them to regain the service of the Harpers Ferry troops ASAP... especially because only 60 Confederate soldiers were there on the 9th.)
It's also worth noting of course that having
only MWIA is basically impossible in any large engagement. It's the stuff of tiny holdouts against overwhelming odds or of fanatics. (Or both, both can work too.)
How does this stack up against McClellan's estimates?
McClellan's estimate of enemy wounded is high compared to Confederate records and is probably high period - but it's the thing he could only estimate.
His KIA estimate for the Confederates is 2,700, and there were 2,468 Confederates buried at Hagerstown (died on the field, later interred there) plus another 112 at Frederick (died of wounds); this comes to 2,580 KIA or died of wounds, which is pretty good, especially when one considers that reportedly some of the troops which captured Harpers Ferry wore blue at Antietam and so would have been buried as Union troops - and that the Hagerstown cemetery is believed to be incomplete, with not all Confederate bodies located and reburied there.
His Captured estimate is not too far off - 2,500 MWIA in the hospitals, 3,000 at Fort Delaware and ca. 225 at Fort McHenry comes to 5,725. (5,613 to avoid double counting of the died-of-wounds.)
As per
http://www.washingtonpost.com/wp-sr...g/civilwar/mcclellan-graphic/index.html?tab=1
this suggests total casualties on the order of 17,000. McClellan's estimate is high but it's not high in unrecoverable casualties.
Interestingly, taking Lee's October 10 state and adding back even our lower bound for Confederate casualties produces a force of nearly 80,000...