The diary of John Quincy Adams is one of the most extraordinary works in American literature. Begun in 1779 at the age of twelve and kept more or less faithfully until his death almost 70 years later, it is both an unrivaled record of historical events and personalities from the nation's founding to the antebellum era and a masterpiece of American self-portraiture, tracing the spiritual, literary, and scientific interests of an exceptionally lively...