American Morse (sometimes called Railroad Morse or Original Morse) is the system Samuel Morse and Alfred Vail used in the 1840s. It looks similar to International Morse but several letters have different patterns, and some characters use internal spacing within a single letter (like the letter C: '.. .').
Some American Morse letters use internal spaces (a short pause within a single character). Internal spaces are denoted by a single space within the morse field; these should be sent shorter than a normal letter gap.
Long dashes (—) in American Morse are sent ~2× the length of a normal dash. The "0" character uses an even longer dash (~5×).
When Samuel Morse demonstrated his telegraph in 1844, the code he used was the original American Morse. As the technology spread internationally, European operators found some of its features (especially the internal-space letters) error-prone over noisy lines. The 1865 ITU conference adopted a cleaner variant, what we now call International Morse, and most of the world switched. American Morse remained in domestic US railroad and Western Union use until the 1960s.
Today American Morse is preserved by historical reenactors, working railroad museums, and a small community of telegraph hobbyists who own and operate vintage Vibroplex 'bug' keys.
About half the alphabet differs. American Morse uses internal spaces within some letters (C = '.. .', O = '. .', R = '. ..') and has different patterns for L, X, Y, Z, and several digits.
Internal-space letters were prone to copy errors over noisy intercontinental lines. The 1865 ITU standardization replaced them with continuous-element letters that copied more reliably, and the rest of the world adopted the cleaner system.
Only by railroad museum reenactors, historical telegraph clubs (like the Morse Telegraph Club), and CW history enthusiasts. No commercial or operational use remains.
Explore all Morse code variants → Morse Code Variants Around the World
