When the colonies came together as the United States, the new nation broke with this 1,450-year practice of religious establishment. Not having a king was radical enough, but even more radical was the new nation’s decision not to establish a national church. The First Amendment to the Constitution, adopted in 1789 and ratified in 1791, prohibited Congress from establishing a church and from preventing citizens from worshiping as they pleased.
The decision frightened many. Western societies had long assumed that most residents would act morally only if they were compelled to participate regularly in the church; Thomas Jefferson disagreed, calling America’s arrangement “the fair experiment.” Prominent nineteenth-century jurist Dudley Field called America’s separation of church and state the world’s “greatest achievement . . . in the cause of human progress.”
The founding fathers adopted this arrangement for several reasons. For one thing, they knew that the experiment had already been tried for over a century, and it had not led to the moral collapse many feared. The exiled Roger Williams had permitted freedom of worship in the colony of Rhode Island, which he founded in 1636. So did Quaker William Penn in Pennsylvania, which he established in 1681. And these colonies were thriving.
Moreover, the founders’ Enlightenment convictions led them to make several arguments on behalf of religious liberty. ...