Stager Cipher No.7 Continued in Use after Abandonment

During the US Civil War, the Union army used route transposition ciphers devised by Anson Stager. One early version, No.7, was widely used in the west but was abandoned in August 1862 when its copy was captured in a raid of a Federal outpost. Still its use as late as 29 September 1862 is known (see another article).

Now its use as late as December 1862 is revealed by the successful codebreaking by Richard Bean (with the help of Claude Opus 5) of unsolved telegrams (ibid.) to Brigadier General Robert H. Milroy (Wikipedia) in Indiana State Library Hosted Digital Collections (URL changed from the one given in the previous article).

G.M. Bascom to Milroy, 4 December 1861

(By Telegraph)

Charleston December 4^th

Brig Genl Milroy
Turkey general enemys head and as give as with army readiness general general bully from in from interfere such necessary detachments contingencies these the major this chap Cox movements quarters keep. will such are movements head to Halleck Kelley tight having to move quarters at immediately orders best general fully by End rope day of of and against your Irressingly Except will orders himself directions daily received hold under this present and to provide Kelley informed command nice finis
G M Bascom
Maj & a. a. G.
79 words

The receiver uses a grid with 12 lines (specified by the indicator) and 6 columns (fixed) to fill words in cells according to the predetermined order of columns, either upward or downward as predetermined. Then, the plaintext can be read horizontally from to to bottom.

Richard's solution is as follows. (The plaintext refers to "Major General Cox", but according to Wikipedia, he was appointed major general on 6 October 1862. Althogh the Library website dates this at "1861", "1862" as put by Richard may be right. Advice from someone who knows the military context is desired. General Kelley (Wikipedia), promoted to brigadier general on 5 August 1861, fits the dating to either "1861" or "1862". (RHM_1862-216_1 is "To Gen Kelley From BF Kelley Dec 2 1862". I wonder whether there were two Kelleys, or this is the same Kelley telegraphing to his own headquarters during some mission.))

General Kelley having received directions from General Halleck to hold himself in readiness to move under orders from army head quarters, this will interfere with movements at present except such as are immediately and [pressingly] necessary give such orders to your detachments as will best provide against contingencies and keep General Kelley and these head quarters fully informed of the enemy's movements by command of Major General Cox.

Maj. Gen. J.D. Cox to Milroy, 3 December 1862

Dated Charleston Dec 3^rd 1862.
Rec'd ... 1862 ... o'clock ... min. M.
To Brig Genl Milroy

China quest whether transportation in reach what is if bully imboden ly to forward Jrsisert also are Cumberland hole that the will the him route confirmed your health information let you also morsefield supply roads with stine
(p.2)
at connection’s for co your far [try] [know] w to fight as me shall hour road your and Kelley x Guusmat road country you of communications avoid you drink to your direction extest Mountain Moonfield morning star answer from can - Winchester by being
(p.3)
can angels co-operate cut a also protect position end time this the cheat what from from as devils so off force to the on pleasant finis
J D Cox
Maj Genl Comd.

The plaintext can be read as follows (where I used brackets [ ] to show his correction of the transcriptions above, in which I followed the website except for formalities).

(1st square)
If your information as to Imboden is confirmed, let me know [by] what route you shall try to reach him, also [how] far forward in the Moorefield Road your [present] transportation will supply your [force], also whether the roads and connections are [such] that with Kelley at Cumberland
(2nd square)
you can co-operate so as to avoid being cut off from your communications by a force from direction of Winchester, also to what [extent] you can protect the Cheat Mountain country from position on the Moorefield Road.

Stager Cipher No.7

When I put the above telegrams in "Unsolved Historical Ciphers", I checked the indicators "Turkey" and "China" were not found in the original cipher books No.9, No.10, No.12, No.1, and No.2, but now I found the route recovered by Richard matches the route of the Cipher No.7. In this early version, the general route (i.e., the pattern of going up/down in a specific order of columns) was fixed, and the indicator specified the number of lines. The choice of indicators ("Turkey" for 12 lines, "China" for 8 lines) is consistent with the known example ("Austria" for 9 lines), which seems to confirm the use of Cipher No.7.

General Kelley to Milroy, 6 November 1862

When I looked again the Indiana State Library website, I found another undecoded telegram with the indicator "China".

U.S. MILITARY TELEGRAPH
Beverly Nov 6^th 1862
By Telegraph from Cambeland 6" 1862
To Genl RH Milroy

China was and stewarts my Experiment possible to your oak Endeavor if dangerous withdraw lest dash or in cherry a destroy cavalry force however it Co-operate telegram sugar received with is for from make it few maple since is sudden rail-road to very force will acorn I you a me the a Imboden day China up to that from and was force neighborhood horse his he fork force up Gap retreating Staunton dog the Harrisonburg fork one if Encamped numbering of scoundrell moorfield about an approached would and Essixs valley fool towards is bricks go a south thousand Country liar Hardy one the by undoubtedly though army once finis.
BF Kelley
Brig Genl

(1st square)
Your telegram received. I will endeavor to co-operate with you[r] force if possible. It is a very dangerous experiment, however, for me to withdraw my force from the rail-road lest Stewart[']s cavalry make a sudden dash and destroy it. Imboden is or was a few day[s] since in
(2nd square)
neighborhood of Moorfield, Hardy Country, his force numbering about one thousand. He was encamped [at] the south fork and if approached by a force from [me?] would undoubtedly go up that fork and th[r]ough [Brock's] Gap to Harrisonburg. [Essex's] army is retreating up the valley once towards Staunton.

Trivia

Sometimes, handwriting in clear text is hard to "decipher". The following specimens look like a series of vertical strokes!

RHM_1863-41_1 (To Schenck, others From Piatt, others Copied Telegrams June 9-13 1863)