Henry David Thoreau was an influential author, philosopher and environmentalist. He graduated from Harvard University in 1837. After college, Thoreau became a school teacher and wrote poems for The Dial but failed as a freelance writer in New York City. After the sudden death of his brother, Thoreau moved to a forest along the shores of Walden Pond, near Concord, Massachusetts. Thoreau's experience at Walden formed the basis of his legendary work Walden, or, Life in the Woods, published in 1854. The book described his memoirs of his life along the beautiful pond as a spiritual quest. Although he spent 26 months on Walden Pond, the book compresses the time as one calendar year (four seasons, each describing a stage of human development).

Thoreau went on to write a two million word journal (over 24 years) about the natural history of Concord and surrounding areas, and wrote "excursion" books about the natural wonders of Cape Cod, Canada, and the Maine Woods. He also wrote essays on fall foliage, seed dispersion, and the wonders of hiking and canoeing. He was among the first to advocate land conservation and wilderness as well as Charles Darwin's Theory of Evolution. Today, Henry David Thoreau is considered America's first environmentalist.

Every creature is better alive than dead, men and moose and pine trees, and he who understands it aright will rather preserve its life than destroy it. - Henry David Thoreau