The History of Morse Code
Morse code was created for the electric telegraph in the United States around 1837 by Samuel Morse and his partners, above all Alfred Vail. The first official message in the code was sent on 24 May 1844.
The code that the world uses today is not that first code. It is International Morse code, a revised version agreed in 1865. This guide follows the code from the first idea to radio, to the distress signal SOS and to its retirement from shipping.
Morse code timeline
| Year | Event |
|---|---|
| 1832 | Samuel Morse has the idea of an electric telegraph on a sea voyage from Europe |
| 1837 | Morse, Joseph Henry and Alfred Vail have a working telegraph system; Morse applies for government funding |
| 1840 | Vail extends the code from numbers to letters and special characters |
| 1843 | The United States Congress grants 30,000 dollars for a line from Washington to Baltimore |
| 1844 | The first official message is sent on 24 May |
| 1848 | Friedrich Gerke revises the code in Germany |
| 1865 | The International Telegraph Convention in Paris makes International Morse code the standard |
| 1890s | Morse code begins to be used for radio |
| 1908 | The distress signal SOS comes into effect internationally |
| 1999 | A satellite-based system replaces Morse code for distress calls at sea |
| 2007 | The United States drops Morse code from its amateur radio licence tests |
The events up to 1844 are from the Library of Congress, which keeps the papers of Samuel Morse. The later dates are from Wikipedia's article on Morse code.
Who invented Morse code?
Morse code carries the name of Samuel Morse, an American painter who turned to invention. The Library of Congress describes how he had the idea in 1832, on a ship back from Europe, after hearing fellow passengers talk about the electromagnet.
| Person | Role |
|---|---|
| Samuel Morse | Had the idea, led the project and gave the code its name |
| Alfred Vail | The young technician who built much of the equipment and extended the code to letters |
| Leonard Gale | A professor who brought the technical knowledge of Joseph Henry's relay |
| Joseph Henry | The scientist whose work on electromagnets and relays made long lines possible |
| Ezra Cornell | The engineer who built the first line |
The first idea of Morse was a code of numbers only, with a book to turn the numbers into words. According to Wikipedia's article, it was Vail who expanded the code in 1840 to include letters, which made the code book unnecessary.
Why is E a single dot?
The most common letters got the shortest patterns, so that messages take less time to send. E, the most common letter in English, is one dot.
Wikipedia's article tells how Vail found out which letters are common. He estimated the frequency of the letters by counting the movable type in the type cases of a local newspaper in Morristown, New Jersey. A printer keeps many pieces of a letter that is used often and few of a rare one.
The result is still visible in the code of today. E and T have one signal each, while rare letters such as J, Q and Y have four.
The first message: 24 May 1844
The first official telegraph message in Morse code was sent on 24 May 1844 from Washington to Baltimore, a distance of about forty miles. The Library of Congress records that Morse sent it from the chamber of the Supreme Court in the Capitol to a railroad station in Baltimore.
The message was a short line from the Bible: "What hath God wrought". The line had been built with the 30,000 dollars that Congress approved in 1843, in the last hours of its session.
After that the telegraph spread fast. Within the lifetime of Morse, cables connected America and Europe.
From American Morse to International Morse code
The code of Vail and Morse, later called American Morse code, was hard to send well. It used dashes of different lengths and gaps inside some letters.
| American Morse code | International Morse code | |
|---|---|---|
| Origin | Vail and Morse, United States, 1840s | Gerke's revision of 1848, agreed in Paris in 1865 |
| Dashes | Several lengths | One length, equal to three dots |
| Gaps inside a letter | Some letters had a longer gap | Always one dot |
| Used | Mainly on American land lines and railroads | Around the world, and for radio |
Friedrich Gerke simplified the code in Germany in 1848. The International Telegraph Convention, signed in Paris on 17 May 1865, took over most of his version as the international standard. According to Wikipedia's article, only four letters kept their pattern from the original code: E, H, K and N.
The standard is still kept by the same body, now called the International Telecommunication Union. Its current text is the recommendation ITU-R M.1677-1.
Morse code and radio
From the 1890s, Morse code moved from wires to radio. Early radio could not carry a voice, but it could switch a signal on and off, and that is all the code needs.
- Ships. Radio operators at sea used Morse code for a century. The distress signal SOS became international in 1908.
- Aircraft. Aviation adopted the code in the 1920s, and from the 1930s pilots had to know it to identify navigation beacons.
- Radio amateurs. Hobby operators made Morse code their own and still use it.
The story of the distress signal is told in the guide on what SOS means.
When did Morse code stop being used?
Morse code was retired step by step at the end of the 20th century, when satellites and digital systems took over. The dates are from Wikipedia's article.
| Date | Event |
|---|---|
| 31 January 1997 | The French Navy sends its last Morse code message |
| 1999 | The Global Maritime Distress and Safety System replaces Morse code for distress at sea |
| 12 July 1999 | The last commercial Morse code message in the United States ends with the words of 1844 |
| 2003 | The ITU makes Morse code optional for amateur radio licences worldwide |
| 23 February 2007 | The United States removes the Morse code test from all amateur radio licences |
The code is not dead. Radio amateurs use it every day, some navigation beacons still identify themselves in it, and the pattern of SOS is known everywhere.
Morse code today
Today most people meet Morse code as a puzzle, a hobby or a piece of history. To read or write it, you no longer need a telegraph key. Our Morse translator turns text into dots and dashes and back, using International Morse code.
Frequently asked questions
- Who invented Morse code?
- Samuel Morse, with Alfred Vail, who extended the code to letters in 1840. Leonard Gale and Joseph Henry contributed to the telegraph itself.
- When was Morse code invented?
- The telegraph system was working around 1837, the letters were added in 1840, and the first official message was sent on 24 May 1844.
- What was the first message in Morse code?
- "What hath God wrought", sent from Washington to Baltimore on 24 May 1844.
- What is the difference between American and International Morse code?
- American Morse code used dashes of several lengths and gaps inside letters. International Morse code, agreed in 1865, has one dash length and regular gaps.
- Is Morse code still used today?
- Yes, mainly by radio amateurs and for some navigation beacons. It is no longer the standard for distress calls at sea since 1999.