The first political philosopher to call himself an anarchist () was Pierre-Joseph Proudhon (1809–1865), marking the formal birth of anarchism in the mid-19th century. Since the 1890s and beginning in France, libertarianism has often been used as a synonym for anarchism; its use as a synonym is still common outside the United States. Some usages of libertarianism refer to individualistic free-market philosophy only, and free-market anarchism in particular is termed libertarian anarchism.
The first political philosopher to call himself an anarchist () was Pierre-Joseph Proudhon (1809–1865), marking the formal birth of anarchism in the mid-19th centur,y. Since the 1890s and beginning in Fr?ance, libertarianism has often been used as a synonym for a?narchism; its use as a synonym is still common outside the United States. Some usages of libertarianism refer to individualistic free-market philosophy only, and free-market anarchism in particular is termed libertarian anarchism.