The five-hundredth anniversary of the Reformation was marked last week with the sotto voce ecumenism that we expect from churchmen these days. In Britain, the Archbishop of Canterbury preached a sermon against division and recorded an interview alongside his Catholic counterpart, the Archbishop of Westminster.

The religious conflicts that followed Martin Luther’s break with Rome seem to belong to a different universe. The schism led to monstrous acts of cruelty and slaughter in the name of a religion which, as both sides notionally accepted, elevates love and forgiveness as supreme values.

Yet, those conflicts also created the U.S. I realize that that’s not how we like to remember it. We tell ourselves that the American Revolution was all about “no taxation without representation” and so, on one level, it was. But that was not the issue that motivated the non-pamphleteering masses. They were stirred by a degree of sectarianism so at odds with our contemporary worldview that we repress the memory.

The evidence is there in the primary documents. Delegates to the First Continental Congress in 1774 raged against the Government’s decision to recognize the rights of the Catholic Church in Quebec:

“By their numbers daily swelling with Catholic emigrants from Europe they might… reduce the ancient free Protestant Colonies to the same state of slavery with themselves.”

The same grievance was repeated, in slightly primmer language, in the Declaration of Independence itself.

Many of the Founding Fathers were undisguisedly anti-Catholic. John Jay, the first Chief Justice of the U.S., argued that every sect should enjoy toleration in his home state of New York “except professors of the religion of the Church of Rome.” Thomas Jefferson believed that Catholicism and political authoritarianism were inseparable: “In every country and in every age the priest is hostile to liberty.” John Adams asked, “Can a free government possibly exist with the Roman Catholic religion?”

What was the basis of that fear, so at odds with their humane and decent views on other issues? At root, the anti-Catholic prejudice of their era was political, not doctrinal. Few colonial Americans were bothered by priestly celibacy or praying for the souls of the dead. But, in their worldview, Catholicism was linked to the autocratic monarchies of France and Spain. They knew little, for example, of the proto-libertarian ideas that had been developed in the sixteenth century by Spanish Jesuits in what we now know as the School of Salamanca. For them, Catholicism was an authoritarian ideology that held sway in the countries against which the English-speaking peoples were habitually at war. Daniel Defoe, the author of Robinson Crusoe, wrote of “a hundred thousand country fellows prepared to fight to the death against Popery, without knowing whether it be a man or a horse.”

The early American settlers preserved a vivid memory of the Puritan hegira that had brought them to the New World. The Pilgrim Fathers had been fleeing what they saw as the idolatry and superstition of an only half-reformed English Church. Now, the King seemed to be sending the serpent into Eden after them.

Quite apart from tolerating Catholicism in Canada, the King had made various attempts in the 1760s to create American bishops. As the great historian of religion in America William Warren Sweet put it, “Religious strife furnished the mountain of combustible material for the great conflagration, while the dispute over stamp, tea and other taxes acted merely as the matches”.

Why is this side of the story so often forgotten? Why is it that, in the words of the historian J.C.D. Clarke, “the virulence and power of popular American anti-Catholicism is the suppressed theme of colonial history"?

Largely, I think, because of what happened next. Against all the odds, a republic born in sectarian violence ended up becoming the first country on Earth where there was total religious freedom. Not just religious tolerance: Plenty of places had had that. But never before had a state allowed every creed and sect equal rights to proselytize.

It turned out to be an extraordinarily successful policy. Those Loyalist Catholics who had fretted about finding themselves a minority in a Puritan state, not least the descendants of Scottish Highlanders who had fought hardest for the Crown, were quick to become patriotic Americans.

Thus, long after Martin Luther’s death, the belief in freedom of conscience that had inspired his followers finally triumphed, albeit an ocean away. That triumph is something truly worth celebrating.

Daniel Hannan, a Washington Examiner columnist, is a British member of the European Parliament.