The nation's oldest federal cultural institution, the Library of Congress serves as the research arm of Congress. It is also the largest library in the world, with millions of books, recordings, photographs, maps and manuscripts in its collections. The Library's mission is to support the Congress in fulfilling its constitutional duties and to further the progress of knowledge and creativity for the benefit of the American people.
The Library of Congress Online Catalog contains approximately 14 million records representing books, serials, computer files, manuscripts, cartographic materials, music, sound recordings, and visual materials. The Online Catalog also displays searching aids for users, such as cross-references and scope notes. The catalog records reside in a single integrated database; they are not separated according to type of material, language of material, date of cataloging, or processing/circulation status.