Answer:
A lot of the Navajo denomination specifically went off to war as code talkers who spoke their native language as a code and were often subjected to harsh treatment despite this fact. Also, the common population of the US didn't know their role in the war and resented them for "Trying to be White" when they wore their uniform.
Read Code talker
by Joseph Bruchac
It's great and super intriguing, I think it turned into a movie too :)
