George Wythe, poor soul, was Jefferson's mentor during law school. He was a man of the Enlightenment and made sure Jefferson knew the law as it was meant to be learned. Wythe also loved books...a lot. So, he got Jefferson into book collecting, thing is, the two started a sort of "contest". To see who could out-read the other. Well, the poor guy was murdered, poisoned with arsenic, but in his will he left Jefferson a big chunk of his library. And Jefferson never stopped collecting