Murray Newton Rothbard was an American economist of the Austrian School who helped define modern libertarianism and founded a form of free market anarchism he termed "anarcho-capitalism".
An individualist anarchist of the Austrian School of economics, Rothbard associated with the Objectivists in his early thirties before allying with the New Left in the 1960s and eventually joining the radical caucus of the Libertarian Party. In the course of his life, Rothbard was associated with a number of political thinkers and movements. During the early 1950s, he studied under the Austrian economist Ludwig von Mises along with George Reisman. He then began working for the William Volker Fund. During the late 1950s, Rothbard was an associate of Ayn Rand and Nathaniel Branden, a relationship later lampooned in his unpublished play Mozart Was a Red. In the late 1960s, Rothbard advocated an alliance with the New Left anti-war movement on the grounds that the conservative movement had been completely subsumed by the statist establishment.
However, Rothbard later criticized the New Left for not truly being against the draft and supporting a "People's Republic" style draft. It was during this phase that he associated with Karl Hess and founded Left and Right: A Journal of Libertarian Thought with Leonard Liggio and George Resch, which existed from 1965 to 1968. From 1969 to 1984, he edited The Libertarian Forum, also initially with Hess (although Hess' involvement ended in 1971). In 1977, he established the Journal of Libertarian Studies, which he edited until his death in 1995.