On the duty of civil disobedience

The slavery crisis inflamed New England in the 1840s and 1850s. The environment became especially tense after the Fugitive Slave Act of 1850. A lifelong abolitionist, Thoreau delivered an impassioned speech which would later become Civil Disobedience in 1848, just months after leaving Walden Pond. The speech dealt with slavery, but at the same time excoriated American imperialism, particularly the Mexican–American War.
In this essay Thoreau argues that individuals should not permit governments to overrule or atrophy their consciences, and that they have a duty to avoid allowing such acquiescence to enable the government to make them the agents of injustice.

«Thoreau was a great writer, philosopher, poet, and withal a most practical man, that is, he taught nothing he was not prepared to practice in himself. He was one of the greatest and most moral men America has produced. At the time of the abolition of slavery movement, he wrote his famous essay On the Duty of Civil Disobedience. He went to gaol for the sake of his principles and suffering humanity. His essay has, therefore, been sanctified by suffering. Moreover, it is written for all time. Its incisive logic is unanswerable.» (Mahatma Gandhi)