His use of images and comparisons based on his studies of animal behavior, life cycles of plants, and the events of changing seasons is best displayed in his best-known book, Walden. Thoreau wrote this book during his pilgrimage at Walden Pond on Emerson"'s property. He lived in a little shanty, which he had built himself. He began his stay in limited isolation on July 4, 1845 as a tribute to his late brother John Jr. And the fact that it started on Independence day also was important.
In the book Walden, Thoreau showcases his simple way of life in order to free himself from the self-imposed social and financial constraints. He also stresses that everyone should create a more intimate relationship between human beings and nature as a remedy to the deadening influence of an increasingly industrialized society. Thoreau said of his stay at Walden, "I went to the woods 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.".
He started to write a complete series of essays that dealt with issues ranging from women"'s rights to temperance, from education to religion, from diet to sex. Thoreau was not a supporter of these reforms. The only movement Thoreau could find an alliance with was abolitionism. "But idealist as he was, standing for abolition of slavery, abolition of tariffs, almost for abolition of government." His most famous essay is "Civil Disobedience," published in 1849. He wrote the essay while he was still living on Emerson"'s property at Walden Pond. He went into town to have a pair of shoes repaired, but he was arrested upon his entrance of the town for not paying a poll tax assessed to every voter. He spent the night in jail and was released the day after once, what is believed to be his aunt, paid the amount in back-taxes he owed. Already against slavery and the fact that his tax dollars were going to be used to support the Spanish-American War, which he was totally against, Thoreau was inspired to write this essay.