Alexander Hamilton had no opinion about Libertarianism, because, living in the eighteenth century, he had no way of knowing what it was. Libertarianism as the label is usually applied today (which I think is where this question is coming from, since Libertarianism is capitalized) was born in the twentieth century. But it is fair to say that modern Libertarians claim a direct intellectual link to, or at least claim inspiration from, many of the ideas brought to bear against Hamilton's financial plan for the United States. In short, Hamilton advocated a plan that would result in increased powers for the new federal government, more federal debt, and increased taxation. He also favored an expansive interpretation of the Constitution that would allow Congress to charter a national bank. Hamilton also advocated the use of force to quell the Whiskey Rebellion in western Pennsylvania. Thomas Jefferson, often cited as a hero of modern Libertarians, was categorically opposed to each of these measures, and Hamilton found his thinking on such issues rather backward. Still, as I mentioned at the beginning of this answer, it is important not to read too many of our modern political debates back into past political debates.