Henry David Thoreau is the author of the famous essay "Civil Disobedience," where he articulates his philosophy on individual resistance to government actions viewed as unjust. Written in 1849, the essay argues that citizens have a moral duty to resist governmental policies that violate their principles, advocating for nonviolent protest. Thoreau's ideas have inspired numerous social movements throughout history, influencing activists like Mahatma Gandhi and Martin Luther King Jr.. His work remains a seminal text in discussions regarding civil rights and government ethics.