President Obama's mention of "nonbelievers" in his inaugural address represents an important broadening of the circle of acceptability in American life, an acknowledgement of our growing diversity and a fuller embrace of the principles articulated in our nation's charter documents.
One of the hallmarks of American life, dating to the 17th century, is its religious pluralism.
The Atlantic seaboard during the colonial period was home to everyone from Puritans, Roman Catholics and Dutch Reformed to Quakers, Baptists, Presbyterians, Swedish Lutherans, Anglicans, Huguenots, Mennonites and Schwenckfelders. Jews arrived in New Amsterdam in 1654, refugees from South America after the Portuguese takeover of Recifé.
Somehow it all worked, especially in the crucible of religious pluralism in the Middle Colonies: New York, New Jersey and Pennsylvania, where William Penn launched his "Holy Experiment" of religious toleration.
In the context of the New World, these religious groups learned to coexist with remarkably little conflict, and when it came time to configure the new nation, the founders in their wisdom elected not to designate any group as the state religion.
"Congress shall make no law respecting the establishment of religion or prohibiting the free exercise thereof," the First Amendment to the United States Constitution reads.
This provision set up a kind of free market for religion in America, allowing religious groups to compete in a marketplace unfettered by government interference. Indeed, American history is littered with religious entrepreneurs (to extend the economic metaphor) who have peddled their wares in this marketplace and thereby contributed to the vigor and vitality of American religious life.
The story of religion in America life has been one of expansion and ever-increasing diversity. Although Roman Catholics were present in the colonial period -- Maryland, named for the wife of Charles I, was founded by Catholics from England -- Catholics arrived in great numbers from Ireland, Germany and Italy over the course of the 19th century.
Many Protestants, their hegemony threatened, resisted, sometimes with violence. Jews from Germany and Eastern Europe came as well.