The United States was in serious trouble. Following its disastrous surprise attack on Pearl Harbor, Japan held the upper hand in the Pacific. Japanese soldiers, wearing American high school and college rings, could speak English fluently and routinely intercepted, and decoded, American military messages. The U.S. needed what has always eluded a country at war: an unbreakable code.
In February of 1942, Philip Johnston, a civilian engineer and World War I veteran, had an idea. What if America’s military forces were to use the Navajo language as the basis of a secret code? Johnston knew something about that language. The son of Protestant missionaries to the Navajo people, he had spent most of his life on, or near, the reservation. He was one of about 30 non-Navajos who could speak the unwritten, extremely difficult language.
Writing a letter outlining his thoughts, Johnston set in motion a life-changing event for 29 Navajo men living on their ancestral homelands. Within months, those men would use their language to develop a code that was never broken during the war.
It remained a national secret until 1968.