In World War 2, US Marines fighting in the Pacific needed to be able to communicate securely on the battlefield. Early in the war, the Japanese had been able to decode some of their encrypted messages. So the Marines turned to members of the Navajo tribe. An unbreakable code based on the Navajo language was quickly developed. And the Navajo Code Talkers went on to participate in all the major Marine operations in the Pacific, helping the Allies to victory.

The full interview with Samuel Tso is available on C-SPAN, along with interviews with other Code Talkers: https://www.c-span.org/video/?459728-1/navajo-code-talker-samuel-tso-oral-history-interview

Photo: 'Code Talker' U.S. Marines George H. Kirk (left) of Ganado, Arizona and John V. Goodluck (right) of Lukachukai, Arizona, both of the Navajo Nation, are photographed before their shelter on a hillside following the American victory of the Battle of Guam, September 1944. (Photo by: Pictures from History/Universal Images Group via Getty Images)