A trove of information, this chart includes immensely detailed soundings; navigational hazards; navigational aids such as lighthouses and light ships; and sailing directions. Also provided is detailed topographical and cartographical information on the adjacent coastal regions, at times extending well inland.

An earlier version of this chart printed on thin paper were bound in the Report of the Superintendent of the Coast Survey for 1857. The example offered here retains the “Preliminary” label in the title but includes many additional soundings, shading in shallow coastal areas, and above all much new information about inland waterways. It was likely issued in 1861 or 1862, as a note at lower right refers to a hydrographic survey conducted in 1860. This dating, and the preliminary “outline” character of the engraving of the inland waterways, raise the possibility that this chart was revised and hurried into print to support Union naval operations during the early phases of the Civil War.

This example is also remarkable for having been printed on heavy paper, clearly intended as a working chart. The condition, with some tears but otherwise clean, suggests that it never made it to sea.

The U.S. Coast Survey
The Office of the Coast Survey is the oldest scientific organization in the Federal Government. It dates to 1807, when President Jefferson established it for the purpose of fostering maritime commerce. The website of the National Oceanic and Atmospheric Administration (NOAA) offers this tribute:

“These men and women (the Coast Survey hired women professionals as early as 1845) helped push back the limits of astronomic measures, designed new and more accurate observational instruments for sea and land surveying, developed new techniques for the mathematical analysis of the mountains of data obtained by the field parties, and further refined techniques of error analysis and mitigation. It was the Coast Survey that led American science away from the older descriptive methods to the modern methods of statistical analysis and the prediction of future states of natural phenomena based on mathematical modeling. Virtually all branches of science, including the social and biological sciences, have adapted similar methodologies and similar techniques in their quest for scientific truth. But, in the United States, it should be remembered that it was the Coast Survey that first trod that path.”

Each Coast Survey chart represented an immense undertaking. For example, this chart of the South Carolina-Georgiacoast is based on data gathered by separate parties focusing on terrestrial topography, triangulation, and hydrography between 1849-1860. At least 18 individual contributors are named on the chart itself, a figure including neither the many lower-ranking members of the survey parties, nor the engravers, printers, &c.

References
OCLC lists a few examples of the chart, though the information given is insufficient to determine the editions being described. Not in Guthorn, United States Coastal Charts; Phillips, List of Maps of America; or Stephenson, Civil War Maps. Antique Map Price Record lists no examples of either state offered for sale in the past 30 years.