Lysander Spooner (1808-1887) was an American political philosopher, abolitionist, and legal theorist. He is best known for his writings on individual liberty and his critique of the U.S. Constitution. Spooner argued that the Constitution was a contract that the government had violated, and he believed in the natural rights of individuals over government authority. Spooner was also a prominent advocate for the abolition of slavery, viewing it as a violation of personal freedom. He founded the American Letter Mail Company to challenge the government’s postal monopoly, promoting free competition in mail delivery. His ideas influenced later libertarian thought and civil disobedience movements.