In January 1964 Medical Literature Analysis and Retrieval System (MEDLARS) was operational at the National Library of Medicine, Bethesda, Maryland.
MEDLARS was the first large scale, computer-based, retrospective search service available to the general public. It was also the first major machine-readable database and batch-retrieval system.
Prior to the release of MEDLARS Frank B. Rogers, Director of the National Library of Medicine, issued a book describing the new system entitled The MEDLARS story at the National Library of Medicine (1963).
Cheryl Rae Dee, "The development of the Medical Literrature Analysis and Retrieval System (MEDLARS)," J. Med. Libr. Assoc., 95 (2007) 416-425.