The American experiment rests on three ideas-"these truths", Jefferson called them-political equality, natural rights and the sovereignty of the people. And it rests, too, "on a dedication to inquiry, fearless and unflinching", writes Jill Lepore in a ground-breaking investigation into the American past that places truth at the centre of the nation's history.

Telling the story of America, beginning in 1492, These Truths asks whether the course of events has proven the nation...