Henry David Thoreau (1817–1862) was an American essayist, poet, philosopher, and naturalist most famous for his profound contributions to early environmental thought and his staunch advocacy of civil liberties. Born in Concord, Massachusetts, Thoreau attended Harvard University where he absorbed the classical curriculum but was more interested in nature, transcendentalism, and writing. His philosophy of simple living and self-sufficiency was revolutionary, articulated compellingly in his canonical work, 'Walden; or, Life in the Woods' (1854), a reflective account of his experiment in near-solitary living by Walden Pond. Exposure to the works of Transcendental maestros like Emerson greatly influenced Thoreau's thinking and literary style, fostering a profound, contemplative prose that extracted meaning and morality from the natural world. Apart from his meditative and naturalistic pursuits, Thoreau is heralded for his tract on civil disobedience; 'Civil Disobedience' (1849), a critical essay asserting that individuals should not permit governments to overrule their consciences and that nonviolent resistance to unjust laws is both rightful and obligatory, was influential on global resistance movements including those led by Gandhi and Martin Luther King Jr. Thoreau's voluminous writings, collected posthumously in anthologies such as 'The Greatest Works of Henry David Thoreau – 92+ Titles in One Illustrated Edition,' continue to inspire readers towards introspection, environmental stewardship, and social justice.