From the mid-1850s submarine cables were laid between continents. The first long distance cables ran between Europe and North America.  In 1865, at the suggestion of the French government, the International Telegraph Union (ITU-UIT) was founded to set the rules of communication.

By 1900, with the invention of and developments made in wireless technology, even ships at sea could be reached. The link between land and sea were coastal radio stations, which were erected in many parts of the world. The telegram was the most vital means of transporting urgent information at high speed via cable and/or wireless to every corner of the globe. In 1900 it took approximately two hours to send a west-bound telegram back to its point of origin.

The person who sent a telegram had to pay for it on a per word basis. So everyone kept messages as short as possible. The resulting language was called "telegram style". Sending a telegram to a ship was extraordinaryly expensive because the sender had to pay landline, coaststation and shipstation charges. A word might cost as much as 1.50 Goldfranks, sometimes even more.

Until the 1980s the maritime radio service was operated manually by especially trained personnel at sea- and at coastal radio stations. The telegrams were transmitted in Morse-Gerke-Code.

The Sputnik satellite, launched in 1957, heralded a new era. From the 1990s on, with the use of the new system, anyone, at anytime and anywhere was reachable. The transfer was provided by the new technology. Thus the telegram found its successors in TELEX, FAX, SMS and e-mail. The times when a telegram was delivered by a messenger to its addressee are gone for ever.

Major Telegraph Lines 1910
Source : Wikipedia