De La Democratie en Amerique, all four volumes, in the original French

According to Wikipedia: "De la démocratie en Amérique (published in ... 1835 and ... 1840) is a classic French text by Alexis de Tocqueville on the United States in the 1830s and its strengths and weaknesses. A literal translation of its title is On Democracy in America, but the usual translation of the title is simply Democracy in America. It is regarded as a classical account of the democratic system of the United States and has been used as an important reference ever since. In 1831, twenty-five year-old Alexis de Tocqueville and Gustave de Beaumont were sent by the French government to study the American prison system. They arrived in New York City in May of that year and spent nine months traveling the United States, taking notes not only on prisons, but on all aspects of American society including the nation's economy and its political system. The two also briefly visited Canada, spending a few days in the summer of 1831 in what was then Lower Canada (modern-day Quebec) and Upper Canada (modern-day Ontario). After they returned to France in February 1832, Tocqueville and Beaumont submitted their report, entitled Du système pénitentiaire aux États-Unis et de son application en France, in 1833. When the first edition was published, Beaumont, sympathetic to social injustice, was working on another book, Marie, ou l'esclavage aux États-Unis (two volumes, 1835), a social critique and novel describing the separation of races in a moral society and the conditions of slaves in America."