At a time of division in the US, biographer Nigel Hamilton returns to a similarly difficult moment to tell the story of a nation’s fate hanging in the balance

Nigel Hamilton is a bestselling biographer, his major subjects including John F Kennedy, Franklin D Roosevelt and Bill Clinton. His new book, Lincoln vs Davis: The War of the Presidents, was published on Tuesday, the US presidential election day when Kamala Harris faced Donald Trump.

Late in his book, Hamilton notes a harsh 1862 verdict on Washington life by Adam Gurowski, a Polish emigre in the state department, anguished words that seem relevant and pungent today.