The United States of America was settled by men and women of deep religious convictions who in the seventeenth century crossed the Atlantic Ocean to practice faith freely. That religious intensity of the original settlers would diminish to some extent over time was perhaps expected, but new waves of eighteenth century immigrants brought their own religious fervor across the Atlantic and the nation's religious revival in the middle of the eighteenth century injected new vigor into the American religious scene.

The results was that a religious people rose in rebellion against Great Britain in 1776, and that most American statesmen, when they began to form new governments at the state and national levels, shared the convictions of most of the constituents that religion was, to quote Alexis de Tocqueville's observation, indispensable to the maintenance of republican institutions. The efforts of the Founders of the American nation to define the role of religious faith in public life and the degree to which it could be supported by public officials that was not inconsistent with the revolutionary imperatives of equality and freedom of all citizens.

Chronology of religious development in America

1607 Virginia settled, Church of England planted in British North America.
1620 Plymouth settled by Pilgrims.
1629-30 Massachusetts Bay Colony founded. Congregationalism planted in British North America.
1634 Maryland founded. Roman Catholic Church planted in British North America.
1635 Roger Williams expelled from Massachusetts. He founds Rhode Island as a haven for religious dissidents.
1654 Jews, fleeing religious persecution in Brazil, arrive in New York City.
1659-62 Quakers hanged in Massachusetts, persecuted in Virginia, victims of the prevailing belief in enforced religious uniformity.
1681 William Penn, leader of the Quakers, receives a charter for Pennsylvania ; Penn establishes religious liberty in
the colony.
1682 Members of German Protestant sects begin arriving in Pennsylvania, attracted by religious liberty.
1689 English Parliament passes Toleration Act, which improves the conditions of dissenters throughout the American
Colonies.
1735-45 The Great Awakening, part of a religious revival throughout the English speaking world, invigorates and
polarizes religious life in America.
1755 Separate Baptists, a product of the Great Awakening, begin proselytizing in the South.
1758 Presbyterian Church, split by the Great Awakening into New Side and Old Side, reunites.
1766 First Methodist meeting (in New York City) in the American colonies.
1776 American independence declared.
1780 Massachusetts constitution adopted; state support of religion provided.
1784 Methodist Episcopal Church established.
1785 Thomas Jefferson's "Bill for Establishing Religious Freedom" passed by Virginia.
1786 U.S. Constitution adopted; religious tests for public service under the federal government prohibited.
1788-89 Protestant Episcopal Church fully established; ties with Church of England cut; Presbyterian Church
established on a new footing.
1789 Bill of Rights passed by Congress proscribes congressional "establishment" of religion and congressional
interference with the "free exercise thereof."
1800 Major revivals in Kentucky, which spread east and initiate a long period of Evangelical dominance in American
religion.
1833 Massachusetts becomes the final jurisdiction to renounce state support of religion.
1834 The great French commentator on American life Alexis de Tocquevile publishes Democracy in America, in
which he observes that Americans consider religion "indispensable to the maintenance of republican
institutions."

The establishment of the American Republic was the first government to be by the people and for the people. Prior to this most countries had ruled by a monarchy. In a monarchy we usually could find a monarchy/church/army state.
In this new Republic we find a State with an army but the church completely free from the government.