I heartily agree with everything my co-bloggers have said about how very unlibertarian it is to sympathize with the Confederacy. One factor that I don’t think was mentioned as to how some otherwise bright, non-racist libertarians might find themselves promoting the Confederacy’s cause is how much some libertarians hate “the Union,” that is, the federal government that emerged out of the Civil War much more powerful than before.
Within the broad tent of libertarianism as it has developed over the last five decades or so, there has always been a significant group whose understanding of America’s role in the world is similar to that of Noam Chomsky and other leftists [update: my impression is that this group was in severe decline starting in the late 70s, but has had a bit of a revival thanks to the wars since 9/11, the growing national security state, and most of all Ron Paul]. Murray Rothbard was the intellectual leader of this group, echoes of which can be seen in some of Ron Paul’s statements on American foreign policy.
If you believe that the United States government has been a massive force for evil in the world, and also object to much of the government’s domestic policy, it’s only natural to wish that the government’s ability to do the damage it wrought had been nipped in the bud. And the most plausible way this could have happened historically would have been for the South to have successfully seceded from the North, leaving a much smaller and weaker central government that would likely have faced further secessionist challenges in the future. This version of the United States would never have become the world power the real United State came, and therefore couldn’t have wreaked the evil the United States purportedly wreaked on the world. [Update: In other words, they see the Confederacy as the first (or second, as some also reference Native Americans) victim of a rising U.S. nationalism and imperialism. And in fairness, even if you don't agree with the "revisionist" view of U.S. foreign policy especially w/r/t the Cold War, the U.S. did become an imperial power, and directly kill tens of thousands in doing so, in the 1890s (see Phillipines, The), and did clumsily intervene in WWI with catastrophic results.]
I’ve never shared been inclined to adopt the libertarian left’s view of foreign affairs, which seems to me to directly incorporate the views of distinctly anti-libertarian leftists (this was brought home to me many years ago when I read a Rothbard essay that attacked the early Zionists for moving to the Land of Israel BUYING land from its owners during Ottoman and Mandate rule in Palestine. Since when is it “libertarian” to attack people for immigrating where they choose and then buying property from its owners?).
Even those libertarians who do adopt a Rothbardian/Chomskyite view of foreign policy, or who for any other reason beyond racism wish the Union would have let the Confederacy secede peacefully, are making a mistake in defending the Confederacy–the enemy of one’s enemy isn’t necessarily a friend. But I just wanted to point out that I think a significant amount of libertarian sympathy for the Confederacy in the circles where it exists is really a product of intense distaste for the U.S. government and its post-Civil War record [along with, as a commenter notes, a general sympathy for the right of secession] rather than a considered view of the Confederacy’s own record.
UPDATE: Less I be misunderstood, let me clarify that (1) a position sympathetic to the Confederacy is not mainstream in libertarian circles, and has gotten ever less so as (a) Rothbard’s influence has declined; and (b) the dominance of southern pro-Confederate historians has given way to more modern scholarship; and (2) the basic position I’m reporting (but oppose) amounts to the argument that slavery was a great evil, but it was inevitably on its way out as in all Western countries, while the nationalism, centralism and militarism of the Union led to the rise of imperialist America (or “ka” if you will) which for over one hundred years has caused, directly and indirectly, untold death and destruction.
I think such libertarians both underestimate the harms that would have been caused by a successful secession, and overstate American evil, especially as compared to who else might have filed that vacuum.