The Library of Congress is the United States' oldest federal cultural institution and 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.
Three Canons of Selection, established in the 1940s, define the collections:
- materials necessary to the Congress and to the U.S. Government officers in performance of their duties;
- materials that express and record the life and achievements of the people of the United States; and
- records of other societies and peoples, especially those of most immediate concern to the people of the United States.
The Library's mission is to make its resources available and useful to the Congress and to the American people and to sustain and preserve a universal collection of knowledge and creativity for future generations. The Office of the Librarian is tasked to set policy and to direct and support programs and activities to accomplish the Library's mission.
The Library serves five audiences:
- Congress — The library provides research support, policy analysis, and training through the Congressional Research Service;
- Professional library world — The library provides cataloging and other bibliographic services and leadership on library technology;
- Executive agencies — The library provides information resources;
- Scholars — The library provides research collections and support; and
- Creative world — The library protects products and preserves traditions.
- Charles A. Goodrum & Helen M. Dalrymple, The Library of Congress 337 (1982).