To whom did Thomas Jefferson tell "I cannot live without books"?

Thomas Jefferson declared, “I cannot live without books” in a letter to John Adams in June 1815. Jefferson fell in love with reading books as a child; he developed an addiction to buying books to feed his insatiable thirst for knowledge. It was reported that he owned between 9,000 and 10,000 books during his lifetime. During his formative period of learning from books, Jefferson was said to have developed a lifelong love for classical literature, poetry, history, mathematics, and geography.

History noted that Jefferson's granddaughter Ellen Wayles Randolph recalled: "Books were at all times his chosen companions." Jefferson himself described his appetite for reading as "canine", and he surrounded himself with books, storing them in various rooms of his mansion so that at any moment —such as when waiting for guests to arrive for dinner — he could read.

Jefferson's library collection came in handy after the War of 1812 when the British burned the Capitol Building and its 3,000 volume library. Jefferson decided to help the US government to replace the loss. He sold a personal collections of almost 7,000 volumes in 1814 to the government of the United States. This collection of books formed the nucleus of the Library of Congress, replacing the collection that had been burned. After the sale, Jefferson began amassing another library for the amusement of his retirement years. By the time of his death, the new library in his home held more than 2,000 of his favorite books.