President Lincoln proclaimed the blockade of all Confederate ports on April 19, 1861. In order to make the blockade effective, the United States Navy was split into two squadrons: the Atlantic Squadron which was to guard the entire Atlantic coast as far south as Cape Florida; and the Gulf Squadron which was responsible for the vast Gulf coast, an area which extended from Cape Florida to the Mexican border. Early in 1862 the Gulf Squadron was divided again into a West Gulf Squadron and an East Gulf Squadron. The area guarded by the East Gulf Squadron extended from Cape Canaveral on the Atlantic to St. Andrew’s Bay on the Gulf. It was this command, with its headquarters in Key West, to which the approaches of Apalachicola were assigned.
Cushman, Jr., Joseph D.
"The Blockade and Fall of Apalachicola, 1861-1862,"
Florida Historical Quarterly: Vol. 41
, Article 8.
Available at: https://stars.library.ucf.edu/fhq/vol41/iss1/8