Description This published “sketch” details Charleston fortifications and provides insight as to how the city was able to withstand repeated attempts by Union warships to enter the harbor. Confederate forces did not evacuate Charleston until February 17, 1865, when they were in danger of losing their only escape route during General William T. Sherman’s “March to the Sea.”Civil engineer W.A. Williams created this detailed sketch that was originally published by L. Prang & Co. of Boston [186-?]. Shows fortifications, street pattern of Charleston, vegetation, and a few soundings. Lithograph map.