On July 12, 2017, we celebrate the 200th birthday of Henry David Thoreau (1817 - 1862), the dropout, nature lover, stubborn and fascinating free spirit and rebel who became an American national icon. On this occasion, the first comprehensive German biography is now being published. Who was this man who, raised as the son of a pencil manufacturer, studied ancient languages at Harvard and read the classical texts in their original form? He jeopardized his career as a teacher because he refused to punish his students with a rod. A 28-year-old reclusive bachelor, he retreated for two years, two months, and two days into a self-built cabin by the forest lake to live outside all societal conventions, and wrote a book about it that has remained essential reading for every American: Walden.