The "92 Code" was first adopted by Western Union in 1859. The reason for this adoption was to reduce bandwidth over the telegraph lines and speed transmissions by utilizing a numerical code system for various frequently used phrases.

       The following code is taken from The Telegraph Instructor by G.M. Dodge-
Some Railroad variation are shown in italics.

       The table at the bottom will show an easy comparison between the original Vail code alphabet (after 1840, and surely by 1844), the Austro-Germanic ("Prussian") code alphabet for Morse instruments (1851), the present Continental Morse code alphabet, and the Bain code alphabet (1846). There were several known revisions of the Bain alphabet, affecting as many as 19 of the characters. The Continental Morse code shown was in use by 1854, and is the same as the modern International Morse Code. The Prussian code is that which was agreed upon at the Vienna Conference of 1851, and was put together by Steinheil. Punctuation, operating signs, and special letters for German (umlauts, ch) are not shown. In the Morse code, the dash is 3 dots in length, the space between dots or dashes in a letter is one dot, the letter spacing is 3 dots, and the word spacing is 6 dots. In the Vail code, a space in a letter has the same duration as one dot (some say two dots), and the T, L and 0 are 2, 4 and 6 dots long, respectively. All of these codes were used with recording instruments, as well as with acoustic receivers.

       It has become quite clear that the Prussian and eventual Continental Morse Codes are based on the original Vail Code, and the Prussian Code is an intermediate step. In this revision, the spaced letters C, O, Y, Z and R were eliminated. R received the previous code for F. C, less frequent in German than in English, received J's old code, and J, not necessary in German, was omitted. Y, an infrequent letter, received a new code including three dashes. Z received a strange new code, as did O, a popular letter. F received the Vail code for Q, and the less frequent letter Q was given a somwhat longer one. X's code went to the more common L, and X received Bain's code for it. P retained its five dots, since this was not yet used for the numeral 5. In fact, the numbers were the same as in Vail. Vail's numbers all consisted of 11 basic (dot) intervals, including --- for 5 and ...... for 6. Codes for the umlaut vowels (ä .-.-, ö ---., ü ..--), as well as the common combination ch (----), also entered the code at this time.

       The next step was to take over the numerals from the Bain code (which might have been suggested by Baumgartner). Numerals now consumed up to 19 dot times, considerably longer than in the Vail code. This meant that P had to have a new code, and the Vail for the numeral 1, now free, was used. The five-element code for O was probably replaced by the Bain code for H at that time. The old numeral 7 went to Z. This was, coincidentally, Steinheil's old code for the letter. The three dashes for O make it the longest of all the vowels. For use with French, Spanish and English, a J was necessary, and a rather long code was chosen. There are also codes for accented letters, such as é (..-..), as well as for ñ (--.--). Already by 1869 there was a long list of special codes for punctuation and procedural signals. The joined AS (.-...) was used for 'wait' even at this early date. The process just described seems plausible, but it would be good if it could be confirmed by documented evidence.

       At the American Telegraph Convention of 1854, there was some talk of altering the Morse alphabet, to eliminate the spaced letters C O R Y Z. The Bain alphabet was proposed for adoption by the New York, Albany and Buffalo company for the Morse services, but rank-and-file opposition arose. No change appears to have been made. The characters for punctuation added to the American Morse Code are shown at the right.

       Some procedural signals used in America by 1860 are the following: OK, all correct (Oll Korrect, 1840); GA go ahead; GM good morning; GN good night; R repeat, please; SSS finished; 1 wait; 13 do you understand?; 31 I do not understand; 23 message for all, usually announcing accident or death, 73 good wishes or compliments. The large numbers of special signals used in various places were becoming reduced and standardized by 1860. A message was said to be "bulled" if it was received incorrectly, as by a sticky sounder. Some United Press reports included characters giving formatting information.