Philip Johnston, the son of a missionary, was born in 1892. When Philip was 4 years old, his family brought him to Flagstaff, Arizona to serve Navajos residing on Navajo Reservation, where he learned to speak Navajo.
When the Japanese Navy attacked Pearl Harbor in 1941, Philip was working as a civilian in Los Angeles. He learned that the U.S. Army was using Comanches to transmit military communications. He then proposed to the United States Marine Corps (USMC) that the Navajo language could also be applied.
Philip demonstrated the utility of using Navajo language to transit military communications with a group of Navajos. Then they agreed that in order to send the military message, they would use word and letter substitution methods to convey messages. Below are examples:
During the war, the work of sending coded messages was extremely serious. The Japanese were able to decode all the messages the U.S. sent. Being able to keep messages secret could make the difference between winning and losing a battle. Philip’s idea of using Navajo languages as a Navajo code to be used during the World War II was a great success.