The American National Library of Medicine (NLM) is part of the United States of America National Institutes of Health (NIH). The NLM is located on the NIH campus in Bethesda, Maryland near Washington, DC.
According to the NLM website, they are the world's largest medical library. Its collection has more than 9 million items including books, journals, technical reports, manuscripts, microfilms, photographs and images.[1]
Its website, http://nlm.nih.gov, has been online since 1993 and provides access to many biomedical databases through Entrez. These databases include MEDLINE and DailyMed as well as many bioinformatics resources.
As opposed to many other nations, the United States does not have an official national library, although the Library of Congress is the de facto official library for fields other than medicine and agriculture. NLM is the official library for medicine, and the National Agricultural Library, in Beltsville, Maryland is the national library for agriculture.