What Is American Morse Code?
American Morse code — also called Railroad Morse or Land-line Morse — is the original dot-and-dash code invented by Samuel F.B. Morse and Alfred Vail in the 1830s for use on electric telegraph machines. It was the dominant telegraph code in North America throughout the 19th century.
Unlike International Morse Code (the modern ITU standard), American Morse uses three distinct signal lengths — a short dot, a regular dash, and a longer dash — plus some characters contain internal spaces within the letter itself. This made it faster for experienced operators but harder to standardise globally.
🇺🇸 American Morse
3 signal lengths: short dot (·), dash (−), long dash (⸺). Some letters have internal gaps. Used on land-line telegraphy in North America, 1840s–1900s. Still used by railroad telegraph hobbyists.
🌐 International Morse (ITU)
2 signal lengths: dot (·) and dash (−) at a 1:3 ratio. No internal spaces. Adopted internationally in 1865, still the worldwide standard for amateur radio, aviation, and military use today.
Try American Morse Code Encoder
Type text to see it encoded in American Morse (⸺ = long dash). Note: American Morse has additional signal lengths not representable in standard audio.
American vs International Morse — Complete Comparison
Teal = American Morse Gold = International Morse Different = codes differ between systems
| Letter | American Morse | International Morse | Status |
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Key Differences Explained
These letters have very different patterns between the two systems. American C is two dashes (⸺ ⸺) while International C is −·−·. This caused the most confusion when switching systems.
American Morse uses a long dash about twice the length of a regular dash. International Morse eliminated this entirely, using only dots and regular dashes for simplicity and better transmission over radio.
Some American Morse letters (like C, O, R, Y, Z) contain a short internal pause within the character itself. This made them ambiguous on radio transmission, where timing is harder to judge than on a wired telegraph key.
History Timeline
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Frequently Asked Questions
What is American Morse code?
American Morse code is the original telegraph code invented by Samuel Morse and Alfred Vail in the 1830s. It uses three signal lengths and internal spaces, unlike the simpler International Morse code used today.
How is American Morse different from International Morse?
American Morse uses short dots, regular dashes, and longer "long dashes" — three different lengths. International Morse uses only two lengths. American Morse also has internal spaces within some letters, which International Morse eliminated entirely.
Is American Morse code still used?
Very rarely. American Morse was replaced by International Morse in the early 20th century. Today it is used only by railroad telegraph heritage groups and history enthusiasts who recreate 19th century telegraphy.
Why was International Morse adopted instead of American Morse?
International Morse is simpler — only two signal lengths — making it easier to transmit over radio where precise timing is harder than on a wired key. It was also standardised globally, allowing operators from different countries to communicate.