The History of Morse Code

Morse code was invented by Samuel F.B. Morse and Alfred Vail in the 1830s for use with the electric telegraph — the first system that allowed messages to travel faster than a horse could carry them. Morse and Vail assigned sequences of dots and dashes to each letter based on frequency of use in English — the most common letter, E, got the shortest code: a single dot. They determined letter frequency by counting the movable type in a local newspaper printing press.

In 1844, Morse sent the first official telegraph message — "What hath God wrought" — from Washington D.C. to Baltimore. Within twenty years, telegraph lines crisscrossed America. The International Morse Code, standardized in 1865, became the global standard used in shipping, aviation, and military communications for over a century.

How Morse Code Works

Every letter, number, and punctuation mark is represented by a unique sequence of dots (short signals) and dashes (long signals). A dash lasts three times as long as a dot. The pause between signals within a letter is one dot length. The pause between letters is three dot lengths. The pause between words is seven dot lengths.

The most famous Morse code signal is SOS — three dots, three dashes, three dots (... --- ...) — chosen in 1906 as the international distress signal because it was simple, distinctive, and impossible to misinterpret. It does not stand for any particular words despite the popular belief that it means "Save Our Souls."

Morse Code Today

While Morse code was largely replaced by satellite communication in the 1990s, it is far from extinct. Amateur (ham) radio operators worldwide still use it — it requires less bandwidth and power than voice transmission and can get through interference that blocks voice signals. The U.S. Navy still trains intelligence specialists in Morse code. It is also used in accessibility technology to allow people with limited mobility to communicate using simple switch inputs.