According to David Barton, Thomas Jefferson thought Sir William Blackstone was foundational to legal practice. However, Jefferson felt a reliance on Blackstone’s Commentaries on the Laws of England by American law students had led to what he called the “degeneracy of legal science.” In fact, Jefferson told Judge John Tyler in this June 17, 1812 letter that he preferred to rely on no British authorities for legal interpretations after the time of the Declaration of Independence. Following his recommendations would “uncanonize” Blackstone. Jefferson said:
But the state of the English law at the date of our emigration, constituted the system adopted here. We may doubt, therefore, the propriety of quoting in our courts English authorities subsequent to that adoption; still more, the admission of authorities posterior to the Declaration of Independence, or rather to the accession of that King, whose reign, ab initio, was the very tissue of wrongs which rendered the Declaration at length necessary. The reason or it had inception at least as far back as the commencement of his reign. This relation to the beginning of his reign, would add the advantage of getting us rid of all Mansfield’s innovations, or civilizations of the common law. For however I admit the superiority of the civil over the common law code, as a system of perfect justice, yet an incorporation of the two would be like Nebuchadnezzar’s image of metals and clay, a thing without cohesion of parts. The only natural improvement of the common law, is through its homogeneous ally, the chancery, in which new principles are to be examined, concocted and digested. But when, by repeated decisions and modifications, they are rendered pure and certain, they should be transferred by statute to the courts of common law, and placed within the pale of juries. The exclusion from the courts of the malign influence of all authorities after the Georgium sidus became ascendant, would uncanonize Blackstone, whose book, although the most elegant and best digested of our law catalogue, has been perverted more than all others, to the degeneracy of legal science. A student finds there a smattering of everything, and his indolence easily persuades him that if he understands that book, he is master of the whole body of the law. The distinction between these, and those who have drawn their stores from the deep and rich mines of Coke and Littleton, seems well understood even by the unlettered common people, who apply the appellation of Blackstone lawyers to these ephemeral insects of the law.
Although his Commentaries were popular, Blackstone opposed American independence. Jefferson, instead of seeing Blackstone as an influence, saw him as a barrier to a distinctly American law profession.
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