This baffling message illustrates a cipher adopted by the Union Army in 1862:

TO GEORGE C. MAYNARD, Washington

Regulars ordered of my to public out suspending received 1862 spoiled thirty I dispatch command of continue of best otherwise worst Arabia my command discharge duty of my last for Lincoln September period your from sense shall duties the until Seward ability to the I a removal evening Adam herald tribune.

PHILIP BRUNER

The address and signature are “covers” that don’t enter into the cipher. The first word, Regulars, is a code indicating that the original message had been written in five columns of nine words each. Tribune, herald, spoiled, Seward, for, and worst are null words; Lincoln is code for Louisville, Kentucky; Adam means General Henry Wager Halleck; and Arabia is code for Major General Don Carlos Buell. The word Period indicates a full stop. This had been the original message:

Louisville, Kentucky
September thirty 1862

General Halleck:

(Adam)   (period)   I           received     last
evening  your       dispatch    suspending   my
removal  from       command.    Out          of
a        sense      of          public       duty,
I        shall      continue    to           discharge
the      duties     of          my           command
to       the        best        of           my
ability  until      otherwise   ordered.

D.C. Buell,
Major General

This message had been enciphered by reading up the fourth column, down the third, up the fifth, down the second, and up the first; inserting the null words; and encoding the most sensitive particulars. The system worked well until July 1864, when Union cipher operator Stephen L. Robinson was captured by Confederate guerrillas and the key seized.

(John Laffin, Codes and Ciphers Secret Writing Through the Ages, 1964.)