Historic water-level records form a major basis for ground-water investigations and water-management decisions on Long Island. Potentiometric-surface maps, one of the major sources of historic data, are scattered within the literature or are available only through the publisher or sponsoring agency. This report presents a comprehensive list of available water-table and potentiometric-surface maps from the 19th century through 1979 with the scale, years represented, and area depicted; complete bibliographic citations are included to facilitate retrieval. The bibliography is preceded by a summary of the hydrologic system and a short history of ground-water development on Long Island, with emphasis on the effects of urbanization as reflected in ground-water levels. A series of six water-table maps from before 1900 through 1979 is presented to illustrate the major historic ground-water trends. (USGS)