Navajo is an unwritten language. In the early part of WW2 Japanese were breaking our codes, so the Military asked the Navajo who were enlisting if they'd become the couriers in the Pacific of our battle plans. They did. Ending up behind enemy lines, they contributed enormously to ending the war. They were kept secret until 1980, (in case of war with Russia or China.) But young sons and nephews, wanting to be like their fathers and uncles joined the Marines and graduated. Their story ran briefly on every morning New show and disappeared.
When we did their story on 'Real People,' months later, I asked the audience to call or write The White House asking for a Presidential citation. President Reagan appeared the following week with that citation!
Today in The Navajo Nation, next to those who killed Custer, The Code Talkers are their greatest heroes!