Henry David Thoreau was a leading transcendentalist who famously lived in a cabin near Walden Pond to simplify his life and connect with nature. His work, Walden, is a reflection on simple living in natural surroundings, while his essay Civil Disobedience argued for individual resistance to an unjust government. A lifelong abolitionist, his philosophy of nonviolent resistance influenced later leaders like Mahatma Gandhi and Martin Luther King Jr. His journals remain one of the most significant records of 19th-century American natural history and philosophical thought.