Parents John and Cynthia Thoreau have a baby boy they name David Henry (he decides to switch the names later). He is the third of the couple's four children.
The family moves to Chelmsford, about ten miles away from Concord, so that John Thoreau can open a grocery store. When it closes three years later, the family moves to Boston and John Thoreau teaches school.
The family moves back to Concord and John takes over his brother-in-law's pencil factory. Henry David Thoreau works at the factory throughout his life.
David Henry and John Jr. Thoreau enroll at Concord Academy, a progressive college prep school in town.
With family chipping in to pay his tuition, Thoreau begins studies at Harvard. A voracious student, he takes far more than the required number of courses.
Shortly after Thoreau's graduation from Harvard, Ralph Waldo Emerson gives his lecture "The American Scholar" to a crowded house at Harvard. Thoreau is the audience and is profoundly moved by the talk. He introduces himself to Emerson and the two become good friends. Thoreau joins the Transcendental Club, an informal gathering of progressive thinkers that meets sporadically at Emerson's house. He also changes his name to Henry David.
Thoreau takes over leadership of the Concord Academy. His brother John soon joins him there as a teacher. Louisa May Alcott is one of their students.
The transcendentalist journal The Dial is founded. Thoreau becomes an avid contributor to the journal, publishing poems, essays and translations.
Thoreau moves into Ralph Waldo Emerson's home, earning his board by doing handyman jobs around the house and babysitting the Emerson children.
John Thoreau Jr. dies in his brother's arms from tetanus he contracted from a shaving cut that became infected. A grieving Thoreau closes Concord Academy.
Thoreau moves into a cabin he built himself on Emerson's property on Walden Pond. He lives there for the next two years and two months. While living there he begins his memoir of the experience, Walden.
Thoreau moves out of his cabin and into Emerson's home to care for his children while Emerson is lecturing.
Thoreau spends a night in jail after refusing to pay his poll tax. The refusal was an act of protest against the American government's policies on slavery and the Mexican-American War.
Thoreau's essay on his experience in jail is published.
Thoreau's first book, a memoir entitled A Week on the Concord and Merrimack Rivers, is published. The book is an account of an 1839 rafting trip he took with his late brother. The book fails to sell, and Thoreau is forced to buy back 700 unsold copies.
Congress passes the Fugitive Slave Law as part of the Compromise of 1850. This makes it a crime to assist escaping slaves. In defiance of the law, Thoreau hides escaping slaves at his family's Concord home.
Walden, Thoreau's account of his time at the pond, is published. The memoir is a success and boosts Thoreau's reputation as a writer.
Thoreau meets the poet Walt Whitman, who gives him a copy of his book Leaves of Grass.
In an attempt to spark a slave rebellion, abolitionist John Brown leads a raid on a U.S. arsenal at Harpers Ferry, West Virginia. Brown is captured and later hanged. Thoreau writes a speech in his defense, A Plea for Captain John Brown, which is later published.
Thoreau, who has struggled with tuberculosis since 1835, travels to Minnesota in the hopes of boosting his failing health. When that doesn't work, he returns to Concord and makes arrangements to have his book The Maine Woods published after his death. He visits Walden Pond, knowing that it will be the last time.
Emerson's friend and colleague Henry David Thoreau dies at the age of 44 and is buried at Concord's Sleepy Hollow Cemetery in a casket covered with wildflowers. Emerson gives the eulogy at his funeral.