The figure of Donald Trump looms over Sarah Churchwell’s new history of American national identity, which highlights the ugliest features of the country’s ingrained traditions of intolerance and bigotry. But it is the current president’s father, Fred, who first leaps off the page in a startling cameo appearance.

On Memorial Day 1927, as Churchwell recounts, the white supremacist, anti-Catholic and anti-Semitic Ku Klux Klan organised a march in New York City’s borough of Queens, home to the German-American Trump family, whose patriarch, Friedrich Trump, had emigrated to the United States in 1885.