Henry David Thoreau was on an errand in town when he encountered Sam Staples, the Concord constable, tax collector, and jailer. Staples took the opportunity to ask Thoreau to pay his back taxes. The independent-minded, highly principled naturalist refused, and Staples politely escorted him to jail.

"The best place for each is where he stands," Thoreau once wrote. When he found himself incarcerated, he took full advantage of the new experience. Fascinated, he "pumped" his cellmate for "the history of the various occupants of that room [and] found that even here there was a history and a gossip which never circulated beyond the walls of the jail." The next morning, his fellow-prisoner was sent "to work at haying in a neighboring field," while Thoreau was told he must leave the jail.

It was not the brevity of his stay that angered him but the interference with his act of conscience and the fuss it caused. For the past six years, he had refused to pay the poll tax (imposed on all males 20 to 70 years old) to protest the institution of slavery. To his great annoyance during his short stay in jail, someone paid it for him.

Thoreau's mother and sisters were active in the Women's Anti-Slavery Society of Concord, founded in 1837, and he had long been involved in the anti-slavery movement, but he preferred to protest through individual action. His family sheltered a number of fugitive slaves, and he would escort them to the next safe house or to an out-of-the-way train station. He delivered powerful lectures against slavery. And he withheld his taxes.

As he later wrote in "Civil Disobedience," he believed "it is not a man's duty, as a matter of course, to devote himself to the eradication of any, even the most enormous wrong; he may still properly have other concerns to engage him; but it is his duty, at least, to wash his hands of it, and . . . not to give it practically his support."

Henry David Thoreau always had "other concerns to engage him." Born in Concord on July 12, 1817, he attended school there, and except for short trips, primarily in New England, rarely left the town he described as "the most estimable place in all the world." After graduating from Harvard in 1837, he taught school for three years and then joined his father at the family pencil factory.

Exceptionally practical and resourceful, Thoreau improved pencil lead by baking the graphite mixture into cylinders and invented a machine that drilled a hole in the wood so the lead cylinder could simply be slipped in. John Thoreau & Company pencils were considered the best on the market. But once Henry had mastered the problem, he moved on. Life, he declared, "is too valuable to put into lead-pencils."

Having never married, Henry Thoreau could choose not "to keep pace with his companions," and, indeed, he heeded "a different drummer." He kept his needs simple. Other than a rowboat and his books, he owned almost nothing. He boarded mostly with his family, and on several occasions, with the Emersons. When he ran out of money, he took a paid job until he was flush again. He could always find work as a surveyor, and he was a skilled carpenter. "He chose to be rich," wrote his friend Emerson, "by making his wants few and supplying them himself."

On July 4, 1845, Thoreau moved into the one-room cabin he had built on land Emerson owned on the shores of Walden Pond. "I went to the woods," he wrote, "because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived."

In the months that followed, he worked in his two-and-a-half-acre vegetable garden, rowed his boat, and observed the smallest details of nature around him. He read, walked, and wrote A Week on the Concord and Merrimack Rivers and the first of seven drafts of Walden. He received visitors often and was himself a frequent dinner guest at his parents' or friends' homes. Besides his one-night stay in jail, his time at Walden was interrupted by a trip north into the Maine forests.

Then two years, two months, and two days after he had moved to Walden, Thoreau "left the woods for as good a reason as I went there. Perhaps it seemed to me that I had several more lives to live, and could not spare any more time for that one."

Walden, or, Life in the Woods was published on August 9, 1854. Unlike his first book, A Week on the Concord and Merrimack Rivers, which sold poorly, sales of Walden were strong from the start. With the exception of a three-year period (1859-1862), the book has never been out of print. It has been translated into almost every language and has sold tens of millions of copies.

Henry David Thoreau was an original thinker and a gifted writer, who produced an extraordinary body of work — journals, essays, poetry, and books. He was also a magnificent naturalist. Taking a walk with him, Emerson remembered, was like walking with an encyclopedia. Thoreau recognized every animal track, every wildflower, and every bird call. He died of tuberculosis in 1862 at the age of 44 and is buried on Authors' Ridge at Concord's Sleepy Hollow Cemetery.