In 1831 French aristocrat Alexis de Tocqueville came to the United States to investigate its prison system. America was then a nation of 13 million people populating 24 states, with a largely unsettled territorial claim stretching westward to the Pacific. Seriously distracted from his original mission, the 25-year-old Tocqueville ended up writing about America's people, culture, history, geography, politics, legal system, and economy in ways so insightful and prophetic that today historian...