Statistics for occurrence #1 of “Charleston harbor” in chapter 3 of Brigadier-General Ellison Capers, Confederate Military History, a library of Confederate States Military History: Volume 5, South Carolina:

...uses and estates along the coast of South Carolina, and retired as refugees into the interior, all the men who were able entering the army. At the time of the fall of Forts Walker and Beauregard, Charleston harbor was defended by Forts Moultrie and Sumter, Castle Pinckney and Fort Johnson, and by batteries on Sullivan's and Morris islands. All these were to be strengthened, and the harbor made secure against...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Charleston Harbor (South Carolina, United States) 1,700 58 36 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.