As the months passed the Union blockade of the Southern coast increased in effectiveness. To make matters worse for the Confederacy, Union amphibious commands were put ashore at a number of points, vital ports and strategic forts were seized, and the number of points at which blockade runners could land their valuable cargos were constantly reduced. On the east coast of Florida, Fernandina, Fort Clinch, Jacksonville, and St. Augustine had been occupied by the Federals in March, 1862. The following month, Jacksonville was evacuated by the Unionists.
Bearss, Edwin C.
"Military Operations on the St. Johns, September-October 1862 (Part I),"
Florida Historical Quarterly: Vol. 42
, Article 5.
Available at: https://stars.library.ucf.edu/fhq/vol42/iss3/5