One of the pillars of the Union’s grand strategy to end the rebellion was to blockade Southern ports and strangle the economy of the Confederacy.  To accomplish this, the Federal government would have to close access to southern harbors.  This would entail stationing warships outside of the ports, or if applicable, cut off access to a port by occupying land at the mouth of the harbor or river feeding the port city.
          Ocean access for the city of Savannah, Georgia was via the Savannah River.  Guarding the mouth of the river was Fort Pulaski.  Construction of Fort Pulaski began in 1829 and was completed in 1857. However, at the beginning of the Civil War it did not yet have its full complement of cannons, and was not officially garrisoned.  On January 3rd, 1860 Governor Joseph E. Brown ordered the Georgia state militia to occupy the fort, sixteen days before the state officially seceded from the Union.
          Fort Pulaski was a masonry fort, its walls constructed of brick and mortar, located on Cockspur Island where the Savannah River empties into the Atlantic Ocean.  The fort had two levels.  The ground level consisted of an open parade ground in the middle, surrounded by five walls.  The western rear wall housed administrative offices, cistern, powder magazines, and officer’s quarters.  The remaining four walls contained cannons mounted in casemates.  Cannons located in these casemates could fire through the walls my means of small windows, completely protecting the gun crews, but limiting their field of fire.  The rear of each casemate was open to the parade ground, but the Confederate garrison quickly constructed wooden walls, called blindages, across these openings, and strengthened them even further by piling earth against the timbers.  Behind the fort was a structure called a demilune.  The demilune was an earth fortification designed to protect the reare entrance to the fort.  The entire fort was surrounded by a moat, which also separated the fortress from the demilune.  To access the fort one must first cross over a drawbridge to the demilune, and from there over another drawbridge to the fort itself.  Both drawbridges were covered by guns from the fort and infantry in the demilune.
          The upper level contained cannons mounted on carriages in barbettes.  These barbette mounts allowed a much wider field of fire for each cannon.  However, the guns merely sat on the top of the fort.  The only cover the gunners had was a small brick wall, or parapet, running along the top of the fort.
          The United States Navy was not very large at the beginning of the war. It was not yet possible to station a blockading squadron of ships outside of every Confederate port and harbor.  There simply weren’t enough ships. However, southern ports whose access to the sea was by river offered a solution.  If Union troops could occupy islands or land at the mouth of these rivers, and construct forts of their own to interdict shipping, then there would be no need for a blockading squadron.  This would free up naval resources for those ports that did require their presence.  If Fort Pulaski could be taken, Georgia’s largest port could be isolated from the outside world.