Native Americans didn't speak English
The English language has been taught in public schools for more than a century. The children of each new influx of immigrants here have been taught it. It is no different today for the children of any nationality if their families are U.S. citizens or residents. Period.
Before we get too caught up in national pride regarding the English language, let's remember that the only true native Americans are Native Americans. Somehow they didn't require the English, Dutch, French and Spanish conquistadors to learn their native tongues - prior to their being massacred by the millions. Our first holocaust.
Furthermore, most of California and the Southwest were Mexican territories - the spoken language being Spanish - before being usurped by the U.S. government a mere 150 years ago or so. Do you think they imposed Spanish-only restrictions for newcomers?
I have been tutoring English Language Arts to Sonoma elementary and middle school students for the past three years. Most of the families I've worked for are Latino and they all want their kids to be proficient in English. That's why they're being tutored, n'est pas?
Our ancestors were all immigrants here once. Maybe these newcomers didn't speak English well or at all, but their children learned it. We who were born here by the grace of fortune, not merit, need to consider the difficulty in learning a foreign language and practice some forbearance. And consider this as well: many regions of the world are multi-lingual. What, pray tell, is wrong with that?