The unique materials of the Rare Book and Special Collections Division, now totaling over 1 million items, include books, broadsides, pamphlets, theater playbills, prints, posters, photographs, and medieval and Renaissance manuscripts. At the center is Thomas Jefferson's book collection, which was sold to Congress in 1815. The Rare Book & Special Collections Reading Room is modeled after Philadelphia's Independence Hall. This room is home to the divisional catalogs, reference collection, and reference staff. Collections are stored in temperature and humidity controlled vaults.