What form of communication was used during WWI to relay messages to the US?

Answer 1

I think it was Navajo ( Lakota ).

Answer 2

Wireless telegraph. British commandos cut the trans-Atlantic telephone cables that connected continental Europe to the U.S. (and all North America) in August 1914. At first, the Germans relayed their messages in diplomatic code to their embassies in the America's to Sweden, which alone had a transmitter powerful enough to reach the U.S. Next, the Germans asked the U.S. to use the Naval Station transmitter on Long Island to receive these messages in diplomatic code and re-transmit them via Western Union to their embassies in the Americas. Eventually, the Germans built a transmitter powerful enough to send to Long Island itself.

In 1917, the German Imperial Foreign Minister Zimmermann sent a telegram to the German Ambassador in Mexico City, (via the U.S. Naval Station on Long Island LOL) instructing him to offer the Mexican government an offensive and defensive alliance against the U.S. The Mexicans were to invade the U.S. from the South and reclaim all Mexican territory lost to the U.S. in the 19th Century. Germany was to wage submarine warfare against the U.S. on the East coast.

The British had broken the German diplomatic code and intercepted the message, sent "over the air." The British helped Americans decipher the message, and the U.S. entered WWI against Germany

Answer 3

Wireless;
Line;
Visual signalling, and
Messenger.
The last was most familiar in the form of despatch riders, who were R Signals. Above unit (eg artillery regiment) level they formed part of the Signals Dispatch Service (SDS) that used many modes of transport. Within units many officers had an 'orderly' who delivered messages and such men were called 'runners' in the infantry. Orderlies in artillery regiments had motor-cycles. Despatch riders were tradesmen and hence paid more that the non-tradesman orderly.

Visual signalling used semaphore flags, marker panels (ground to air), heliographs or signalling (Aldis) lamps. Although it was extensively taught pre-war its use rapidly died out as the war progressed after being used effectively in the East African campaign in 1940, apart from some very specialised uses. However, a specialised form of visual signalling, marker panels, was used from ground to air. Unlike some continental armies the British made only limited use of coloured flares and the pigeon service was not used by field artillery, although the Australian artillery did deploy with pigeons on at least one occasion in the SW Pacific!

Wireless and line communications were either voice or telegraph. On wireless voice was called 'R/T' (radio telephony) and telegraph was 'W/T' (wireless telegraphy), line telegraphy was sometimes called 'L/T'. There was a third mode, teleprinter (teletype-writer in the US) a form of telegraph, but this was not generally used for dedicated artillery communications at any level in the British Army.

Morse code was used for telegraph, lamp and heliograph signalling, and in 'continuous wave' (CW) mode on normal HF radios in units. However, this was not just simple Morse code, in addition to the alphabet and numbers there were codes for some special characters such as "/". There was also a large set of two and three letter brevity codes for all manner of military expressions.

Answer 4

homing pigeons and runners