Henry David Thoreau
Born in Concord, Massachusetts in 1817, Thoreau was a writer, poet, tax resister and abolitionist who was part of a group of New England philosophers known as "Transcendentalists."  He is perhaps best known today for his book about nature and the simple life, Walden, which he wrote after living in a small cabin at the edge of Walden Pond.  He spent a night in jail (he hoped it would be longer) for refusing to pay taxes as a form of protest against the Mexican-American war and slavery.  His notion of using "civil disobedience" to bring about social change played a major role in 20th century activism. 
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