U.S. Coast Survey A.D. Bache Supdt., Sketch Showing The Progress of The Survey on the Atlantic Gulf of Mexico and Pacific Coast of The United States to November 1865

A nice overview map showing the progress of the Survey on all coasts. A legend explains the details of the status of triangulations, latitude/longitude determinations, topography, hydrography, offshore soundings, and deep-sea soundings. A table of statistics is also shown in the lower right. The Pacific Coast is shown as a sub-sketch. The interior of the contintent has some indications of the route of the triangulations from the east towards the west as far as St. Louis as well as the Missouri and Tennessee Rivers. The Gulf Stream is shown as well.

IMPORTANT NOTE:

All of our United States Coast Survey (USCS), United States Coast & Geodetic Survey (USC&GS), and similar maps and charts have been professionally unfolded and flattened using humidity baths, semi-permeable membrane, and drying blotter techniques. Most others you typically see on eBay have not been, and worse, are quickly and crudely unfolded for the low-quality photos you see. Unfolding these maps in that way is damaging and weakens them. Please be aware.