July 12, 1817	Henry David (christened David Henry) Thoreau is born in Concord, Mass., to John and Cynthia (Dunbar) Thoreau.
1828-33	Schools at the Concord Academy
1833-37	Attends Harvard College, finishing 19th in his class of 44. Ralph Waldo Emerson addresses Thoreau's graduating class with his "American Scholar."
1837	Meets Emerson, who becomes his mentor and friend
1838-41	With his elder brother John, reopens the defunct Concord Academy, which features nature walks and reasoned discussion instead of rote learning and corporal punishment
1840	Publishes "Aulus Persius Flaccus" and "Sympathy" in The Dial, the new Transcendentalist quarterly
1841	Closes Concord Academy because of John's poor health; Henry moves into Emerson's family home as his protégé
January 1842	John dies unexpectedly of lockjaw; Ralph Waldo Emerson's son Waldo dies of scarlet fever
1842-43	Publishes "Natural History of Massachusetts," "Walk to Wachusett" and "A Winter Walk"
1843	Tutors William Emerson's children on Staten Island, New York.
1844	Assists in his father's pencil factory. In April, Thoreau and a friend accidentally start a fire in Walden Woods that consumes 300 acres. Emerson purchases lot of woods near Walden Pond; the Fitchburn Railroad lays tracks along Walden Pond and into Concord.
July 4, 1845	Begins his 26 month experiment living in a cabin near Walden Pond
June 1846	Spends night in jail for refusing to pay a poll tax
September 6, 1847	Leaves Walden Pond and lives in Emerson's house while Emerson lectures in England
1848	Begins sporadic career as professional lecturer
Late 1848	Thoreau approaches publisher W.D. Ticknor with his manuscript A Week on the Concord and Merrimack Rivers and Walden. Ticknor agrees to publish Walden after Thoreau underwrites publication of A Week. After returning from Europe, Emerson advises Thoreau to risk underwriting the publication. Thoreau agrees, though their friendship suffers
1849	Publishes "Resistance to Civil Government" ("Civil Disobedience"). A Week is published with mixed reviews. Only 200 copies are sold. In his journal, he writes: "I have now a library of nearly nine hundred volumes, over seven hundred of which I wrote myself." Postpones Walden and does not work on it from 1850-52.
1852-54	Begins to revise the Walden manuscript, which will see seven drafts
1853	Publishes portions of "A Yankee in Canada"
1854	Publishes Walden; or, Life in the Woods and "Slavery in Massachusetts"
1855	Publishes portions of "Cape Cod" as a serial
1857	Publishes "Chesuncook" as a serial
February 1859	Takes over pencil factory after his father dies; lectures frequently
January -- early May 1861	Works on both "Wild Fruits" and "The Dispersion of Seeds."
May 12 -- July 14, 1861	Travels with Horace Mann, Jr., to Minnesota in search of a drier climate after a year fraught with illness
May 6, 1862	Dies in Concord of tuberculosis. Hundreds attend Thoreau's internment at Author's Ridge at Sleepy Hollow Cemetery.
1866	Fitchburn Railroad turns Walden Pond into a tourist / amusement destination: "Lake Walden"
1872	Bronson Alcott creates a cairn of stones at the Walden cabin site