For example, it used to be that wherever a child came from, he or she was expected to learn from teachers who only spoke English.
Over time, opponents of such "immersion" English programs introduced bilingual programs, where children could be taught in both English and their native language.
Now, as CBS News Correspondent Sandra Hughes reports, the pendulum may be swinging back the other way.
In a state where 140,000 children begin each school day speaking Spanish, the days of bilingual education may be numbered. This November, Arizona voters are expected to close the books on this 30-year teaching tradition.
The alternative: an abrupt return to English immersion, which is already in place in neighboring California.
"I've always believed English immersion is the most sound and sensible way to learn a language," says Margaret Garcia-Dugan, principal at Glendale High School near Phoenix.
"Students that have bilingual education are not proficient in reading and writing and speaking in English," she says.
And recent statistics would appear to back her up. In California, where English-only became law two years ago, statewide reading scores for English learners jumped nine percentage points. Math went up 14 points.
And scores soared even higher in Oceanside, where Christian Dominguez began an English immersion class after arriving from Mexico last year.
"My friend Jonathan said 'Wow, you can talk a lot of English!'" Dominguez says.
Oceanside's success shocked its superintendent, who never believed the English-only law would work.
"Thirty years of commitment to something is hard to set aside but I think I was wrong, I have to admit that," says Superintendent Ken Noonan. "They love school, they're absorbing the English, learning quickly."
But there are still many educators who believe in the bilingual approach. Most of them argue California's success is due to other factors like smaller class size. And with billions of education dollars at stake, bilingual supporters have a vested interest in keeping the programs alive.
So with their entire profession under attack, publishers, college professors and bilingual teachers are vowing to fight.
"There has not yet been developed a program that outperforms bilingual education," says Arizona State Senator Joe Eddie Lopez. "And so we just don't think we ought to get rid of it."
But facing hard evidence that English immersion works, bilingual education may be making an exit from the American classroom.