Although the board recommended that Fernandina, Florida, be taken as the southern anchor of the blockade, two other positions were captured before Fernandina. A pair of minor forts on the Outer Banks of North Carolina near Cape Hatteras were taken by Union forces on August 28–29, 1861, and on November 7 a major fleet operation at Port Royal, South Carolina, resulted in the capture of a deep-water harbor midway between Savannah and Charleston. The Hatteras expedition had been planned as a raid; the plan called for it to be held only long enough to block up Hatteras Inlet. However, it was transformed into an incursion, and led early in the next year to a full invasion, the so-called Burnside Expedition, which included the capture of Roanoke Island and established the Union Army permanently in eastern North Carolina. Port Royal in Union hands was soon used a base to make the blockade of Savannah almost complete, but Charleston was not so easily sealed off. Use of its harbor by blockade runners was curtailed, but to close it completely required some of the bitterest and most persistent ground action of the war.