What specific laws does Thoreau have in mind when he writes, "Unjust laws exist: shall we be content to obey them, or shall we endeavor to amend them, and obey them until we have succeeded, or shall we transgress them at once?" How were these laws Thoreau had in mind transgressed in his era?
If the injustice is part of the necessary friction of the machine of government, let it go, let it go: perchance it will wear smooth–certainly the machine will wear out… but if it is of such a nature that it requires you to be the agent of injustice to another, then I say, break the law. Let your life be a counter-friction to stop the machine. What I have to do is to see, at any rate, that I do not lend myself to the wrong which I condemn. An individual who breaks a law that conscience tells him is unjust, and who willingly accepts the penalty of imprisonment in order to arouse the conscience of the community over its injustice, is in reality expressing the highest respect for the law. An unjust law is itself a species of violence. Arrest for its breach is more so. Now the law of nonviolence says that violence should be resisted not by counter-violence but by nonviolence. This I do by breaking the law and by peacefully submitting to arrest and imprisonment. One has not only a legal, but a moral responsibility to obey just laws. Conversely, one has a moral responsibility to disobey unjust laws.