The right wing loves to say that Americans are a “Christian nation”, but that assertion is NOT true!
It is true that a majority of Americans are born to the Christian faith, whether Catholic or any of the many Protestant sects, or Eastern Orthodox.
But our Founding Fathers, while born Christian, were in many cases skeptics about organized Christianity, and certainly had no mission to promote a church-state combination, a theocracy, as they knew of the turmoil and sufferings of such combinations in European history, including Great Britain, France, the German states, and Czarist Russia, along with the effects of Islam on the Middle East, Asia, and Africa.
Therefore, the Constitution of the United States made clear to keep separation of church and state separate, and there is no statement of America as a “Christian nation” by the Founding Fathers.
There are plenty of statements by many Founding Fathers, including Thomas Jefferson, James Madison, Alexander Hamilton, George Washington, John Adams and others that advocated separation of church and state, and a sense of skepticism about organized Christianity being part of government.
We also have evidence that conservative Christian pastors condemned the Constitution after its adoption because of the fact that it was a document which, clearly, was secular in nature, and some called the Constitution an atheistic document, which shows how hard the Founding Fathers had worked to undermine the creation of a theocracy, which would allow persecution of non Christians or non believers in religion itself.
After the Civil War, the right wing Christian pastors tried repeatedly to amend the Constitution to make America a Christian nation and make references to Jesus Christ, but those attempts failed, and the only religious reference that would become normal was to say “In God We Trust” on American coinage.
The deleterious effect of this movement among right wing Christian pastors, however, led to anti Catholic and anti Jewish practices and laws locally, discriminating against the immigration of so called “undesirable” groups.
Additionally, for a long period of time, commerce was limited by “Blue Laws”, which banned economic activities on Sundays, finally overcome about 50 years ago, as if someone does not wish to do shopping or other commerce on the Christian Sabbath, that is their choice, but should not be imposed on others, one of the examples of what happens when theocracy and its narrow mindedness is allowed to take hold.
So America is NOT a “Christian nation”, but rather a nation of a diverse number of religious groups, with a majority of Christian sects, including Catholicism, something the majority Protestants did not wish to acknowledge!