This fact book, compiled to fill the need of practicing librarians and researchers for recent data on public libraries, contains statistics concerning or relevant to the U.S. public library system. Data on all aspects of American public libraries are summarized from such sources as annual reports, journal articles, surveys, books, doctoral theses, government studies, and other unpublished reports and documents. Most of the data included were published or gathered between 1973 and 1978, and none predate 1970. Information on public libraries in countries other than the U.S. has been included whenever the public library systems in those countries were comparable with the American model. Entries in the factbook are arranged alphabetically by topical subject heading, and bibliographic citations to the sources of the statistics given in each entry are included. (JL)