The American West, like this country itself, was a refuge for religious movements. The Mormons moved to Utah - or Zion as they preferred to call it - because of its isolation from the rest of the country.
But it didn't quite work out as expected. The federal government in 1857 insisted that the Mormons end the practice of polygamy - and sent a military force to occupy Utah and convert the territory and its theocracy into a secular state.
The First Amendment, of course, promised any American the right to religious freedom, something that 19th century judges surely believed did not include a man married to more than one woman. The conflict between Mormon theology and the federal government disappeared shortly before the 20th century began when Wilford Woodruff, president of the Church of Jesus Christ of Latter-day Saints, issued a manifesto ending plural marriage.
However, a few splinter groups, small in numbers, refused to recognize Woodruff's actions - and continue to practice polygamy in Utah, Arizona and throughout the West.
Two American principles collided here, and the institution of marriage was valued more than religious freedom. The power of government won, and a religion lost.
It's fairly easy to draft national principles - even lofty ones. But our national character is only tested when one of those principles runs head-on into another. Then the nation has to pick winners and losers.
One such test is on the horizon.
The Wisconsin Supreme Court ruled in June that parents may use school vouchers to send their children to private religious schools. Civil-liberties groups say this decision means tax dollars will be used to support religious schools - a violation of the constitutional separation of church and state.
But little more than a century ago, most of America's education was directed by religious groups. States, and occasionally the federal government, saw nothing wrong with spending tax dollars on a good Christian education.
The problem was the definition of Christian, which was essentially limited to Protestants. Catholics and other religious minorities formed their own schools, without public support, because they were not included.
Then came public schools.
"Early in our history we had unity at the expense of diversity," says Charles Haynes, an expert on religion and public education with The Freedom Forum in Arlington, Va. "We still need a way of forging a nation out of our differences. It can't be an enforced conformity, religious or any other way."
Haynes says the concept of public education is built from the idea of e pluribus unum - from the many, one - one of the founding principles of this nation.
This is the principle under review now. Is it still worthwhile to promote "from the many, one"? Or would we rather have our "own" values, vouchers and schools?
Also, if taxpayer funds are suitable for religious schools, then who is going to define religion? The list of churches that might want to tap into this funding is as long as the list of religions in the Yellow Pages - every sect from Anglicans to Zoroastrians.
This is not idle conjecture: A proposed Los Angeles charter school says it wants to use a teaching method based on the work of L. Ron Hubbard, founder of the Church of Scientology.
Sure, there is a principle at work here; vouchers are important. But even in a country as diverse as America, in a country founded on religious liberty, it is difficult to imagine sending a taxpayer voucher to a school run by, for instance, a 21st century polygamist group.
If this debate centers on principles, then I'll stick with e pluribus unum.
Mark N. Trahant's column appears Sunday and Thursday in the Local News section of The Times. His phone message number is 206-464-8517. His e-mail address is email@example.com