Civil Disobedience is an essay by the transcendentalist writer and philosopher Henry David Thoreau. It was published in 1849 under the title, Resistance to Civil Government. In the essay, Thoreau espouses the need to prioritize one's conscience over the dictates of laws and criticizes American social institutions and policies—especially slavery and the Mexican American War.
Civil Disobedience had only limited impact during Thoreau’s lifetime, but its influence would eventually become widespread. The work inspired India's Mahatma Gandhi, and later, ideas from it were embraced by Martin Luther King, Jr., and the American Civil Rights Movement.