They were both rooted in the same Enlightenment ideals of universal human rights, and they both erupted during the waning decades of the 18th century. Why then did the American and the French revolutions produce such radically different results: a contentious but stable democracy on one side of the Atlantic, the Terror and the triumph of Napoleon on the other?
The question is old but still stimulating and provocative, as historian Susan Dunn demonstrates anew in Sister Revolutions: French Lightning, American Light (Faber and Faber; 258 pages; $26). In presenting her lively analysis, Dunn, a history professor at Williams College, relies...