Henry David Thoreau (July 12, 1817 – May 6, 1862) was an American author, poet, philosopher, abolitionist, naturalist, tax resister, development critic, surveyor, historian, and leading transcendentalist.He is best known for his book Walden, a reflection upon simple living in natural surroundings, and his essay Civil Disobedience, an argument for individual resistance to civil government in moral opposition to an unjust state.