In addition to his economic and political writings, Rothbard also wrote about history. He looked beneath the "victor's history" of government schools and court intellectuals, usually finding the true story to be quite different from the conventional "wisdom." His view of history was that of an eternal struggle between liberty and authority, a "race between state power and social power." His "revisionist" history of colonial and revolutionary USAmerica was presented in a four volume set Conceived in Liberty. His books on the history of economic thought are also notable.
If we look at the black record of mass murder, exploitation, and tyranny levied on society by governments over the ages, we need not be loath to abandon the Leviathan State and ... try freedom. - Murray Rothbard, For a New Liberty
Rothbard has two excellent introductory books to libertarianism. For a New Liberty: The Libertarian Manifesto is the more accessible and popular book with an outline of theory and applications to modern day issues. For those with a more academic bent, The Ethics of Liberty gives a more detailed explanation and justification of the philosophy of Liberty. Both are available online.