The US Military employed many code talkers in World War I and World War II who could transmit coded messages enemy forces wouldn’t understand. The code talkers would come from Native American tribes who would use codes developed based on their native languages that would be difficult to translate.
Top photo: Choctaw soldiers from World War I.
Middle Photo: Comanche code talkers from the 4th Signal Company of the U.S. Army during World War II.
Bottom photo: Navajo code talkers on Saipan in World War II.