Library of Congress

National Library of America. The largest library in the world. 1800 was established as a research library of the American legislature according to the act of the US Congress, and moved to Washington with the Congress. Originally reserved for members of Congress and senior government officials, it is now open to federal government departments and the public. By the end of 1987, the collection had reached 85,985,800 volumes (pieces), including 470 languages. Among them, there are more than 20,000 printed books, more than 7 million microforms, more than 20,000 audio-visual materials and more than 3.8 million maps. Social science and political science documents are the focus of the collection, especially books on American history and culture, and scientific and technological documents are mainly aviation. Since 190 1, the library has issued the catalogue card of the Library of Congress, since 1927, and since 197 1, it has officially issued the machine-readable catalogue (MARC-II) tapes to libraries and information systems, and started cataloging in the edition. Library of Congress Classification and Library of Congress Bibliography have a wide influence in the library field. The National Consultation Center, established in 1962, is funded by the National Science Foundation and undertakes the task of providing clues to solve problems for scientific and technical personnel in various scientific fields. At the same time, the Guide to American Intelligence Sources was published in volumes, introducing intelligence consulting institutions. The Library of Congress has become a reference center for Congress, government, academia and ordinary readers, an international exchange and lending center, a national catalogue center, a collection center for government publications and United Nations materials, a cooperation center between domestic and foreign libraries, and a library science research center.