I Am Native American (cherokee)

Your dad probably grew up in the 50's and 60's when western or cowboy-indian movies were popular and where "the only good indians were dead indians". As a kid, I imagine his choices were to either pretend that he wasn't or get teased and/or beaten up by other kids.

Native Americans were depicted as savages, or alcoholics, or go-fers with funny hats. Tonto was maybe the lone exception, but much of that was because he was the fateful servant of the Lone Ranger. Also, he was tall, spoke clearly, was brave, and didn't drink or hang round with bad company. Had Tonto been short and overweight, or had he occasionally overindulged in wine or women, it's unlikely that he would have been cast as the exception :)

Per tales from the old timers, there was a bit of an ethnic purge in the US in the late teens and early 20's. Until then, there were still French, Spanish, German and everything-else speaking communities and neighborhoods in the US. And suddenly there was like a big move to English only where English was force-fed to the kids and there was a sense of shame levied on those stuck in non-English speaking cultures. The western movies of the 30's, 40's and 50's probably fed off the white-English speaking. In reality much of the old wild west was actually Spanish speaking and blended assorted creole heritage.

The only thing we can now do about deceased parents is to understand and be compassionate about what they had to endure, and try to make for a more considerate and compassionate America as we move forward. Be proud of his having survived whatever horrors he experienced. You are the living proof of his triumph over the adversities.