From the back cover of the book: "The author, the director of the Charleston Museum and a retired naval officer, has brought together, mainly from original sources, more information on the seige than is to be found elsewhere." (American Historical Review)
Concerning the move to Sumter, the book says in part, "He [Anderson] instructed Hall to delay unloading his personnel and cargo under the pretext of finding suitable quarters at Fort Johnson. ... When the last man from Moultrie was on Sumter, the two guns were fired, signaling recall of the schooners waiting at Fort Johnson with the women, children and supplies aboard. The captain of one of the schooners, realizing that he had been duped, put up a fight and had to be overcome with force."
I discovered at the Fort that mac_truck knew more about the situation inside the Fort at the time of Doubleday's arrival (i.e., how many laborers were present) than the two park rangers on duty did. I got different numbers from the two rangers, and it was clear they were making educated guesses. Mac, on the other hand, had provided some documentation to support his case. Hats off to mac on that one.
As lentulusgracchus once observed, these threads are like a graduate seminar on the war.