Rothbard attended Columbia University, where he received a Bachelor of Arts degree in mathematics in 1945 and a Ph.D. in economics in 1956. The delay in receiving his Ph.D. was due in part to conflict with his advisor, Joseph Dorfman, and in part to Arthur Burns’s rejecting his dissertation. Burns was a longtime friend of the Rothbards and their neighbor at their Manhattan apartment building. It was only after Burns went on leave from the Columbia faculty to head President Eisenhower’s Council of Economic Advisors that Rothbard’s thesis was accepted and he received his doctorate. Rothbard later said that all his fellow students were extreme leftists and that he was one of only two Republicans at Columbia at the time.

As a young man, Rothbard considered himself part of the Old Right, an anti-statist and anti-interventionist branch of the Republican Party. In the 1948 presidential election, Rothbard, “as a Jewish student at Columbia, horrified his peers by organizing a Students for Strom Thurmond chapter, so staunchly did he believe in states’ rights”. He was a member of The New York Young Republican Club.

Rothbard began to consider himself a “private property anarchist” in 1950 and later began to use “anarcho-capitalist” to describe his political ideology. In his anarcho-capitalist model, the system of private property is enforced by protection agencies, which compete in a free market and are voluntarily supported by consumers who choose to use their protective and judicial services. Anarcho-capitalists describe this as “the end of the state monopoly on force”.

In 1953, Rothbard married JoAnn Beatrice Schumacher (September 17, 1928 – October 29, 1999), whom he called Joey, in New York City. JoAnn was a historian and was Rothbard’s personal editor and a close adviser as well as hostess of his Rothbard Salon. They enjoyed a loving marriage and Rothbard often called her “the indispensable framework” of his life and achievements. According to Joey, the Volker Fund’s patronage allowed Rothbard to work from home as a freelance theorist and pundit for the first 15 years of their marriage. The Volker Fund collapsed in 1962, leading Rothbard to seek employment from various New York academic institutions. He was offered a part-time position teaching economics to engineering students at Brooklyn Polytechnic Institute in 1966 at age 40. The institution had no economics department or economics majors and Rothbard derided its social science department as “Marxist”, but Justin Raimondo writes that Rothbard liked teaching at Brooklyn Polytechnic because working only two days a week gave him freedom to contribute to developments in libertarian politics.

In 1954, Rothbard, along with several other attendees of Mises’s seminar, joined the circle of novelist Ayn Rand, the founder of Objectivism. He soon parted from her, writing among other things that her ideas were not as original as she proclaimed, but similar to those of Aristotle, Thomas Aquinas and Herbert Spencer. In 1958, after the publication of Rand’s novel Atlas Shrugged, Rothbard wrote her a “fan letter”, calling the book “an infinite treasure house” and “not merely the greatest novel ever written, [but] one of the very greatest books ever written, fiction or nonfiction”. He also wrote: “[Y]ou introduced me to the whole field of natural rights and natural law philosophy”, prompting him to learn “the glorious natural rights tradition”. Rothbard rejoined Rand’s circle for a few months, but soon broke with Rand again over various differences, including his defense of what he described as “anarchism”.

Although he self-identified as an Austrian economist, Rothbard’s methodology was at odds with that of many other Austrians. In 1956, Rothbard deprecated the views of Austrian economist Fritz Machlup, stating that Machlup was no praxeologist and calling him instead a “positivist” who failed to represent the views of Ludwig von Mises. Rothbard stated that in fact Machlup shared the opposing positivist view associated with economist Milton Friedman. Mises and Machlup had been colleagues in 1920s Vienna before each relocated to the United States and Mises later urged his American protege Israel Kirzner to pursue his PhD studies with Machlup at Johns Hopkins University.

During the 1940s, Rothbard became acquainted with Frank Chodorov and read widely in libertarian-oriented works by Albert Jay Nock, Garet Garrett, Isabel Paterson, H. L. Mencken, and Austrian economist Ludwig von Mises. In the early 1950s, when Mises was teaching in the Wall Street division of the New York University Stern School of Business, Rothbard attended his unofficial seminar. Rothbard was greatly influenced by Mises’s book Human Action. He attracted the attention of the William Volker Fund, a group that provided financial backing to promote right-wing ideologies in the 1950s and early 1960s. The Volker Fund paid Rothbard to write a textbook to explain Human Action in a form that could be used to introduce college undergraduates to Mises’s views; a sample chapter he wrote on money and credit won Mises’s approval. For ten years, the Volker Fund paid him a retainer as a “senior analyst”. As Rothbard continued his work, he enlarged the project. The result was his book Man, Economy, and State, published in 1962. Upon its publication, Mises praised Rothbard’s work effusively.

From 1969 to 1984, he edited The Libertarian Forum, also initially with Hess (although Hess’s involvement ended in 1971). The Libertarian Forum provided a platform for Rothbard’s writing. Despite its small readership, it engaged conservatives associated with the National Review in nationwide debate. Rothbard rejected the view that Ronald Reagan’s 1980 election as President was a victory for libertarian principles and he attacked Reagan’s economic program in a series of Libertarian Forum articles. In 1982, Rothbard called Reagan’s claims of spending cuts a “fraud” and a “hoax” and accused Reaganites of doctoring the economic statistics in order to give the false impression that their policies were successfully reducing inflation and unemployment. He further criticized the “myths of Reaganomics” in 1987.

In an essay condemning “scientism in the study of man”, Rothbard rejected the application of causal determinism to human beings, arguing that the actions of human beings—as opposed to those of everything else in nature—are not determined by prior causes, but by “free will”. He argued that “determinism as applied to man, is a self-contradictory thesis, since the man who employs it relies implicitly on the existence of free will”. Rothbard opposed what he considered the overspecialization of the academy and sought to fuse the disciplines of economics, history, ethics and political science to create a “science of liberty”. Rothbard described the moral basis for his anarcho-capitalist position in two of his books: For a New Liberty, published in 1973; and The Ethics of Liberty, published in 1982. In his Power and Market (1970), Rothbard describes how a stateless economy might function.

Rothbard continued in this role until 1986. Then 60 years old, Rothbard left Brooklyn Polytechnic Institute for the Lee Business School at the University of Nevada, Las Vegas (UNLV), where he held the title of S.J. Hall Distinguished Professor of Economics, a chair endowed by a libertarian businessman. According to Rothbard’s friend, colleague and fellow Misesian economist Hans-Hermann Hoppe, Rothbard led a “fringe existence” in academia, but he was able to attract a large number of “students and disciples” through his writings, thereby becoming “the creator and one of the principal agents of the contemporary libertarian movement”. He kept his position at UNLV from 1986 until his death. Rothbard founded the Center for Libertarian Studies in 1976 and the Journal of Libertarian Studies in 1977. In 1982, he co-founded the Ludwig von Mises Institute in Auburn, Alabama, and was vice president of academic affairs until 1995. Rothbard also founded the Institute’s Review of Austrian Economics, a heterodox economics journal later renamed the Quarterly Journal of Austrian Economics, in 1987.

According to economist Peter Boettke, Rothbard is better described as a property rights economist than as an Austrian economist. In 1988, Boettke noted that Rothbard “vehemently attacked all of the books of the younger Austrians”.

Rothbard split with the Radical Caucus at the 1983 national convention over cultural issues and aligned himself with what he called the “right-wing populist” wing of the party, notably Lew Rockwell and Ron Paul, who ran for President on the Libertarian Party ticket in 1988. Rothbard “worked closely with Lew Rockwell (joined later by his long-time friend Burton Blumert) in nurturing the Ludwig von Mises Institute, and the publication, The Rothbard-Rockwell Report; which after Rothbard’s 1995 death evolved into the website, LewRockwell.com”.

In 1989, Rothbard left the Libertarian Party and began building bridges to the post-Cold War anti-interventionist right, calling himself a paleolibertarian, a conservative reaction against the cultural liberalism of mainstream libertarianism. Paleolibertarianism sought to appeal to disaffected working class whites through a synthesis of cultural conservatism and libertarian economics. According to Reason, Rothbard advocated right-wing populism in part because he was frustrated that mainstream thinkers were not adopting the libertarian view and suggested that former KKK Grand Wizard David Duke and Wisconsin Senator Joseph McCarthy were models for an “Outreach to the Rednecks” effort that could be used by a broad libertarian/paleoconservative coalition. Working together, the coalition would expose the “unholy alliance of ‘corporate liberal’ Big Business and media elites, who, through big government, have privileged and caused to rise up a parasitic Underclass”. Rothbard blamed this “Underclass” for “looting and oppressing the bulk of the middle and working classes in America”. Rothbard noted that Duke’s substantive political program in a Louisiana governor’s race had “nothing” in it that “could not also be embraced by paleoconservatives or paleolibertarians; lower taxes, dismantling the bureaucracy, slashing the welfare system, attacking affirmative action and racial set-asides, calling for equal rights for all Americans, including whites”.

Rothbard supported the presidential campaign of Pat Buchanan in 1992 and wrote that “with Pat Buchanan as our leader, we shall break the clock of social democracy”. When Buchanan dropped out of the Republican primary race, Rothbard then shifted his interest and support to Ross Perot, who Rothbard wrote had “brought an excitement, a verve, a sense of dynamics and of open possibilities to what had threatened to be a dreary race”. Rothbard ultimately supported George H. W. Bush over Bill Clinton in the 1992 election.

Rothbard held strong opinions about many leaders of the civil rights movement. He considered black separatist Malcolm X to be a “great black leader” and integrationist Martin Luther King Jr. to be favored by whites because he “was the major restraining force on the developing Negro revolution”. Rothbard rejected the idea of “compulsory integration” and felt that “self-help, pride, thrift, Negro businesses, etc… cannot hope to flourish within the context of the black reality in America: permanent oppression by the white ‘power structure.’ None of these good and libertarian things can be achieved without first and foremost, getting the white-run U. S. and local and state governments off the backs of the Negro people.” In 1993 he rejected the vision of a “separate black nation”, asking “does anyone really believe that … New Africa would be content to strike out on its own, with no massive “foreign aid” from the U.S.A.?”. Rothbard also suggested that opposition to King, whom he demeaned as a “coercive integrationist”, should be a litmus test for members of his “paleolibertarian” political movement.

Rothbard died of a heart attack on January 7, 1995, at the age of 68. He was buried in Oakwood Cemetery, Unionville, Virginia.

After Rothbard’s death in 1995, Lew Rockwell, president of the Mises Institute, told The New York Times that Rothbard was “the founder of right-wing anarchism”. William F. Buckley Jr. wrote a critical obituary in the National Review, criticizing Rothbard’s “defective judgment” and views on the Cold War. The Mises Institute published Murray N. Rothbard, In Memoriam which included memorials from 31 individuals, including libertarians and academics. Journalist Brian Doherty has summarized Buckley’s obituary as follows: “[W]hen Rothbard died in 1995, his old pal William Buckley took pen in hand to piss on his grave”. Hoppe, Rockwell, and Rothbard’s colleagues at the Mises Institute took a different view, arguing that he was one of the most important philosophers in history.

In a 2011 article critical of Rothbard’s “reflexive opposition” to inflation, The Economist noted that his views are increasingly gaining influence among politicians and laypeople on the right. The article contrasted Rothbard’s categorical rejection of inflationary policies with the monetary views of “sophisticated Austrian-school monetary economists such as George Selgin and Larry White”, [who] follow Hayek in treating stability of nominal spending as a monetary ideal—a position “not all that different from Mr [Scott] Sumner’s”.