The essay Civil Disobedience (1849) –one of the most significant texts of political thought– calls American citizens to refuse to pay the taxes imposed by the then government of James Polk, a government that accepted slavery as a legal right and declared war on Mexico in 1846, aiming to expand slavery into the territories it would conquer.

Thoreau articulates here the doctrine of "passive resistance" to authority through the manifestation of disobedience. This, the author says, is mandated by a sense of justice and an awareness of duty. A similar sentiment was expressed by the romantic poet P. B. Shelley in his poem "The Mask of Anarchy" (1819), a work that profoundly influenced Thoreau.

For Thoreau, the expression of political disobedience as a mandate of his conscience was nothing more than the realization of his individuality. Disobedience becomes the method of defending the freedom of conscience and individual rights.

Among the political thinkers who developed the idea of political disobedience in the political conditions of their time, attributing the paternity of the term to Thoreau, the most significant were Mahatma Gandhi and Martin Luther King. The first major writer to pay attention to Thoreau's text in the 1866 edition was Leo Tolstoy, who praises his ideas in Resurrection.