Former president Thomas Jefferson, who advocated the expansion of the library during his two terms in office, responded to the loss by selling his personal library, the largest and finest in the country, to Congress to “recommence” the library. The purchase of Jefferson’s 6,487 volumes was approved in the next year, and a professional librarian, George Watterston, was hired to replace the House clerks in the administration of the library. In 1851, a second major fire at the library destroyed about two-thirds of its 55,000 volumes, including two-thirds of the Thomas Jefferson library. Congress responded quickly and generously to the disaster, and within a few years a majority of the lost books were replaced.
After the Civil War, the collection was greatly expanded, and by the 20th century the Library of Congress had become the de facto national library of the United States and one of the largest in the world. Today, the collection, housed in three enormous buildings in Washington, contains more than 17 million books, as well as millions of maps, manuscripts, photographs, films, audio and video recordings, prints, and drawings.