What's an Old Whig, you ask? I ran across the term in Friedrich A. Hayek's _The Constitution of Liberty_. The old whigs opposed King James II's oppressive government. I can't remember right off if they got their start during the Puritan theocracy of the mid-1600s. I may be confusing them with the Cavaliers, who were Catholics and supported the Restoration of the Monarchy under Charles II.
Anyway, Lord Shaftesbury and John Locke were the leaders of the early movement, and their political works were built upon by Trenchard and Gordon of _Cato's Letters_ fame in the 1730s. America's founders read these works and the writings of Cicero and came up with our form of government.