No American historian of the nineteenth century has so enchanted, irritated, and impressed his contemporaries and successors as Henry Brooks Adams. He was and is his country's greatest historian, and its most elusive. His achievement was various: he helped to fashion and define the school of "scientific" history, so that his History of the United States of America During the Administrations of Thomas Jefferson and James Madison (1884-1891) is a work of stamina and grace that may, with some indulgence, be mentioned in the same breath with Edward Gibbon's History of the Decline and Fall of the Roman Empire; he was among the first and best of American medievalists, and his Mont-Saint-Michel and Chartres (1904) is an unpretending and quirky combination of travel literature, intellectual history, and architectural celebration; his autobiography, philosophical dissertation, and memoir, The Education of Henry Adams (1907), is the most compelling and intractable of American fin-de-si...