The Pope standing before a joint session of Congress, delivering a formal address after having been received at the White House by the president. Shivers would have gone down the spines of some earlier generations of Americans at the very thought of these events, sure signs of the impending destruction of the United States and its noble experiments in democracy and self-rule. The visit of Pope Francis, however, has been an occasion not for lament but rather for widespread celebration. The welcomes he has received in Washington, New York, and Philadelphia are enthusiastic – getting to see him is the “toughest ticket” everywhere, regardless of the seeker’s religion (or lack of it) – and the crowds throw into sharp relief the long American tradition of anti-Catholicism and hostility to the papacy. The greetings accorded Francis are a measure of how far we have come.

Europeans discovered the “New World” of the Americas at the same historical moment that more than a millennium of unified Christendom was fragmenting into Catholic and Protestant traditions, and the religious controversies of the Old World came inevitably to the new one. The English settlers of the territory that eventually became the United States had been touched in a particularly powerful way by the Reformation. The colonists of the South, mostly Anglican, had specifically rejected the authority of the pope over their church, and the Puritan settlers of New England were even more vigorous in their denunciations of “popery,” identifying him as the very Anti-Christ mentioned in the Bible. In 1647, Massachusetts passed the first of several “anti-priest” laws, declaring any clergyman “ordained by the authority of the pope” to be by definition “an incendiary and disturber of the publick peace.” If a priest dared to enter the colony, he would be banished – if he pitched up because of shipwreck, he was allowed a decent interval to leave on his own – and if he came back he could be hanged. No priest ever tested the law, but the colony’s leaders were probably serious about the whole thing. Four Quakers who violated a similar statute banning them were executed on Boston Common, to the evident delight of onlookers.

These traditions never entirely faded, returning periodically in waves, but they began to lose some of their force after the American Revolution. Most new states adopted the principles of religious freedom embodied in the First Amendment to the federal constitution, though in some places hostility toward Catholics died hard. In drafting the New York state constitution, for example, John Jay tried unsuccessfully to deny Catholics the right to vote or even to own property. In the 1850s, nativist political parties swept to power briefly in several states, promising to restrict the voting rights of the growing numbers of largely Catholic immigrants. One favorite proposal was to increase, from six years to twenty-one, the amount of time it took for an immigrant to become a citizen. A child born in this country in that era had to wait twenty-one years before voting, “Know Nothing” legislators reasoned; why shouldn’t an immigrant have to wait that long too, even if already an adult?

Hostility toward the pope in particular persisted. In 1854, construction of the Washington Monument in the nation’s capital was stalled for more than two decades after Pope Pius IX, following the example of other foreign dignitaries, sent an inscribed stone for inclusion in the obelisk. Vigilantes hammered the stone to pieces and threw them into the Potomac. (The Civil War and a shortage of money contributed to the delay.) Close observers of the monument today can still see that the marble changes color about a third of the way up, where the project had been suspended. To contemporary sensibilities such actions seem deeply un-American and even irrational, the product of pure prejudice. But the context of the times reveals a foundation for the recurring belief that Catholics made unreliable citizens.

Until 1870, the pope was not only the leader of the Catholic Church worldwide, he was also the king of a country: the Papal States. A swath of central Italy with constantly shifting boundaries, this was a nation, presided over by “Il Papa-Re” – the “Pope-King.” In addition to his religious duties, the pope supervised a government with the full range of civic responsibilities, from operating a postal service and building railroads to engaging in diplomacy in the frequently treacherous waters of international affairs. These secular powers would be taken away from the pope with the unification of Italy in 1870, but before then his religious and secular roles were mixed together, and this was a cause of suspicion to many in America. Did the religious loyalty that Catholics owed to their pope imply political loyalty as well? Many Americans thought so. In becoming citizens, all immigrants were routinely asked to forswear allegiance to their former rulers – the kings and queens of England, for example – and that was as it should be. But did Catholics nonetheless retain some allegiance to their foreign “Pope-King,” and if so were they not fundamentally at odds with (or even subversive of) American ideals? Catholics themselves insisted that their fealty to the pope extended only to religious matters, not to politics, but so long as the pope remained a political leader, the question was open.

Even after the pope had become an entirely religious figure, suspicions remained, most evidently in politics. Large Catholic voting blocs in American cities in the first half of the twentieth century suggested to some that Catholics would simply vote en masse for whoever their priests, seen as agents of the pope, told them to. Moreover, if the pope could tell ordinary voters what to do, couldn’t he do the same with Catholic office holders? In 1928, such fears clearly played a role in the defeat of presidential candidate Al Smith, the first Catholic to be the nominee of one of the major parties. He was even planning, his more excitable opponents maintained, to build a tunnel from Washington to Rome to make it easier for the pope’s minions to get back and forth to shape policy. (Smith had other problems too: he was a “wet” at a time when support for Prohibition was still strong.) And the issue returned in 1960, until John Kennedy settled the matter with his famous speech to the ministerial association in Houston, insisting that he was the Democratic candidate for president, not the Catholic candidate. Since then, as Catholics have continued to assimilate, they have become perhaps the quintessential swing voters in national elections, now favoring Republicans (Ronald Reagan), now Democrats (Bill Clinton), and eagerly sought by both sides.

In recent times, the pope has emerged as a broadly-defined moral voice as well as the leader of a particular church, and that is the role that Francis has emphasized since taking office. In 1965, Paul VI, the first pope to visit the United States, addressed the United Nations with an emotional plea of “Jamais plus la guerre” – “War never again.” Francis’s own recent letter urging action to care for the environment continues that tradition, as does his insistence that European governments address the current migration crisis. All this underlines his appeal across the spectrum of religious belief, as he seeks to promote common cause for the general public good.

What could be more American than that?