U.S. library, the largest and one of the greatest of what may be considered national libraries.
Founded in Washington, D.C., in 1800, it was housed in the Capitol until the building was burned by British troops in 1814; it moved to permanent quarters in 1897. In addition to serving as a reference source for members of Congress and other government officers, it is outstanding among the learned institutions of the world, with magnificent collections of books, manuscripts, music, prints, and maps. It contains some 18 million books, 2.5 million recordings, 12 million photographs, 4.5 million maps, and more than 54 million manuscripts.