The Law Library of Congress contains the largest collection of United States, foreign, comparative, and international law and legislation in the world. The law collection currently consists of more than one million titles comprising over 2.9 million volumes, and over 3 million microform items, which can be located by searching the online catalog. About 80,000 of these volumes are housed in the Law Library Rare Book collection. The Law Library has amassed a comprehensive collection of U.S. federal and state legal material, a superior collection of legal works from all nations of the world, and materials from international and regional multinational organizations. Comprehensive geographically, the collection also spans all periods of law, from the most ancient to the most contemporary. All systems of law—common, civil, customary, and religious—are represented, as are all topics within the field of law, including comparative law and the law of Indigenous peoples.

Serving as the de facto law library of the United States, the Law Library of Congress acquires legal information in the publishing format designated as official by each issuing body, and retains the best archival copy available. The Law Library collection serves two purposes: First, U.S. and foreign legal specialists/attorneys on staff develop “law practice libraries” for their jurisdictions. This enables them to provide thorough responses to increasingly complex legal questions from Congress, the courts, and executive branch agencies. Questions may require information from 273 existing national and subnational jurisdictions and 28 international/regional organizations. To support this work, approximately 60% of the collection is in vernacular languages, requiring multi-lingual staff to develop, curate and use the collection. Second, the collection supports onsite and remote library patrons. The Law Library collects legal and legislative materials in paper and digital formats, and actively produces digital surrogates.

Additionally, the collection includes nearly 100,000 reels of microfilm and 3.25 million pieces of microfiche. On average, the collection grows annually by 40,000 volumes, 1,800 reels of microfilm, 92,000 pieces of microfiche, 40,000 serial pieces and 50,000 official gazettes. Please see our Collection Policy Statement for more information.