4. Long Island Triangulated: Nineteenth-Century Maps and Charts of the U.S. Coast Survey


A new era began in the mapping of Long Island and the nation when the U.S. Coast Survey started its activities on Fire Island. The Coast Survey was the first federal agency to produce detailed and accurate maps of large areas of the United States.

The Coast Survey began its nationwide mapping with the construction of a baseline on Fire Island (shown below). Between 1833-1843 the Coast Survey produced highly detailed manuscript (hand written) maps of Long Island. These were used as the basis for a number of published maps that appeared in the years after 1844.


U.S. Coast Survey, Sketch B., No. 2, Showing the Triangulation & Geographical Positions in Section No. II from New York City to Point Judith, 1851.
Shows base line on Fire Island and triangulation network used in first survey by U.S. government.

(Courtesy State University of New York at Stony Brook.)



U.S. Coast Survey, Detail of a Manuscript map showing Huntington area, 1837.
(Courtesy State University of New York at Stony Brook.)



U.S. Coast Survey, Middle Part of the Southern Coast of Long Island, 1857.
Detail from a published Coast Survey map.
(Courtesy State University of New York at Stony Brook.)



U.S. National Ocean Survey, Oyster and Huntington Bays, 1996.
Modern nautical chart made by the National Oceanic and Atmospheric Administration, the successor agency to Coast Survey.
(Courtesy State University of New York at Stony Brook.)




Many high-quality images of nineteenth-century coastal charts of Long Island are available from a site on the Web maintained by the National Oceanic and Atmospheric Administration. Click here to go to NOAA's Historical Map and Chart Collection.

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