Henry David Thoreau was born July 12, 1817, in Concord, Massachusetts. His father, John, worked at various occupations, including farmer, grocer, and pencil manufacturer. His mother, Cynthia, was the daughter of a minister and ran a boarding house to supplement the family's income. Henry was the third of their four children.

Thoreau attended school in Concord and, with financial help from relatives, went on to Harvard University, where he graduated in 1837. By that time, Ralph Waldo Emerson, who would be Thoreau's lifelong mentor and friend, had moved to Concord. Emerson and Thoreau were members of a thriving group of transcendentalists that included Bronson Alcott (father of author Louisa May Alcott), Margaret Fuller, and others. (The core of transcendentalist philosophy is the idea that divinity and truth reside throughout creation and are grasped intuitively, not rationally.)

Rather than settling into one of the professions for which Harvard had prepared...