From the National Library of Medicine (http://www.nlm.nih.gov):
In 1837 the National Library of Medicine was founded. In the early years, it was simply the reference collection for the office of the Army Surgeon General. In 1862, the National Library of Medicine was founded and as the two institutions grew, they often shared space. For two years after the assassination of President Lincoln in 1865, the Library was housed in the vacated Ford's Theater.
It was not until 1936 that the NLM was transferred to the control of the Department of Health, Education, and Welfare. In 1962 it moved to its present location on the campus of the National Institutes of Health in Bethesda, Maryland.
In addition to its collection--including a many rare and old books on medical science--one of the National Library of Medicine's services was the publication of the Index Medicus: a monthly index of medical articles published in over 5000 other periodicals. The Index was published from 1879 until December of 2004. The information is still available through the NLM's free PubMed/MEDLINE databases, which contains over 16 million articles.