In an address to the National Prayer Breakfast (8 February 2018), President Donald Trump called the United States a ‘nation of believers’. As evidence, he reminded his audience that the American currency includes the phrase ‘In God We Trust’ and that the Pledge of Allegiance is ‘under God’. Trump omitted that, in their present state, these godly references date only from the Cold War era of the 1950s. Secularists had in the nineteenth century repulsed several efforts to have mottos of this ilk permanently imposed upon the nation or the constitution. Trump should – but will not – read Timothy Verhoeven, who addresses Church-State separation after the Revolutionary era, and who provides sober reflection on the complexities of the dividing line between politics and religion in American history.

Readers will probably be unsurprised by the historical US penchant for embracing moral reforms of a quasireligious character, from alcohol and drug prohibition to anti-prostitution and antislavery activism to anti-abortion laws. Perhaps less obvious or understood for the foreign observer than the swirl of evangelical religious influence is the strict separation of church and state, a distinction which does not allow a wide latitude for state support of religious schools, as in contemporary Australia.