When World War I broke out in the Spring of 1914, thousands of Navajo men and women volunteered their services to the war efforts. They fought in the overseas places of France, Germany, and Italy and received numerous awards and decorations for outstanding duty; many were cited for bravery under fire. A large number of Navajo women on the Navajo Reservation were active in Red Cross and several Navajos bought Liberty Bonds and were involved in other war efforts.
The Navajo Code Talkers Program was established in September 1942 as the result of a recommendation made the previous February by Mr. Philip Johnston to Major General Clayton P. Vogel, USMC., Commanding General, Amphibious Corps, Pacific Fleet, headquartered at Camp Elliott, California. Mr. Johnston, the son of a missionary to the Navajo tribe, was fluent in the language, having lived among the Navajos for 24 years. He believed that use by the Marine Corps of Navajo as a code language in voice (radio and wire) transmission could guarantee communications security.
Mr. Johnston's rationale for this belief was that Navajo is an unwritten language and completely unintelligible to anyone except another Navajo, and that it is a rich fluent language for which code words, in Navajo, could be devised for specialized military terms, such as the Navajo word for "turtle" representing a tank. With cooperation of four Navajos residing in the Los Angeles area, and another who was already on active Naval service in San Diego, Mr. Johnston presented a demonstration of his theory to General Vogel and his staff at Camp Elliott on February 25, 1942. Marine staff officers composed simulated field combat messages, which were handed to a Navajo, who then translated it into tribal dialect and transmitted it to another Navajo on the other side of the line.