Library of Congress

The Library of Congress is the research library of the United States Congress, the de facto national library of the United States of America, and the oldest federal cultural institution in the United States. Located in four buildings in Washington, D.C. , as well as the Packard Campus in Culpeper, Virginia, it is the largest library in the world by shelf space and number of books. The head of the Library is the Librarian of Congress, currently James H. Billington.