Henri D. Thoreau was born on July 12th, 1817, in Concord, Massachussett. His father was a minor businessman of that town.
He was educated at Harvard. After graduating in 1837, at the age of 20, he began an unsuccessful career of school teaching. His experience with nature in the raw, derived from a canoe trip on the Merrimack and Concord rivers in 1839 left him with a profound impression which was the starting point of his natural philosophy.
He was a Trancendentalist and a friend of Ralph W. Emerson.
For two years, from July 1845 to September 1847 he lived in a cabin that he built by his own hands, on the shores of Walden Pond, on land owned by Emerson.
Walden; or life in the wood, his masterwork was the product of this experience.
Later, he became more involved in politics. As a result of his opposition to the Mexican War (1846-1848) and his one night imprisonment for refusing to pay his poll tax in protest, he produced the essay on "Civil Disobedience".
His activism in the antislavery struggle resulted in some of his most celebrated essays.