Lysander Spooner (1808 - 1887) was an American political philosopher, essayist, pamphlet writer, Unitarian, abolitionist, legal theorist, and entrepreneur of the nineteenth century. He was a strong advocate of the labor movement and severely anti-authoritarian and individualist in his political views. Spooner's most famous writing includes the seminal abolitionist book The Unconstitutionality of Slavery, and No Treason: The Constitution of No Authority which opposed treason charges against secessionists.