Lysander Spooner (1808-1887) was an American individualist anarchist, entrepreneur, political philosopher, abolitionist, supporter of the labor movement, and legal theorist of the 19th century. He is also known for competing with the U. S. Post Office with his American Letter Mail Company, which was forced out of business by the United States government. He has been identified by some contemporary writers as an anarcho-capitalist, while other writers and activists believe he was anti-capitalist and even socialist for vocalizing opposition to wage labor. Spooner attained his greatest fame as a figure in the abolitionist movement. His most famous work, a book titled The Unconstitutionality of Slavery, was published in 1846 to great acclaim among many abolitionists but criticism from others. From the publication of this book until 1861, Spooner actively campaigned against slavery. He published subsequent pamphlets on Jury Nullification and other legal defenses for escaped slaves and offered his legal services, often free of charge, to fugitives. He harshly condemned the Civil War and the Reconstruction period that followed. In response, he published one of his most famous political tracts, No Treason.