Lt. Gen. Longstreet took charge of the Department of Virginia and North Carolina on February 25 and initiated his Tidewater Operations. He directed D.H. Hill, commander of the North Carolina District, to advance on the Union stronghold of New Berne with about 12,000 men. Maj. Gen. William H.T. Whiting, who commanded the Wilmington garrison, refused to cooperate. After an initial success at Deep Gully on March 13, Hill marched against the well_entrenched Federals at Fort Anderson on March 14_15. Hill was forced to retire upon the arrival of Union gunboats. The city’s garrison was heavily reinforced, and Hill withdrew to threaten Washington, North Carolina.
References
CWSAC Battle Summaries, National Park Service (http://www2.cr.nps.gov/abpp/battles/bycampgn.htm)
Fort Moultrie was the oldest and was the headquarters of the garrison.
Fort Sumter, by contrast, dominated the entrance to Charleston Harbor and was thought to be one of the strongest fortresses in the world once its construction was completed; in the autumn of 1860 work was nearly done, but the fortress was thus far garrisoned by a single soldier, who functioned as a lighthouse keeper.
Anderson lowered the Fort Sumter Flag and took it with him to the North, where it became a widely known symbol of the battle, and a rallying point for supporters of the Union.
Fort Henry and Fort Donelson were the sole positions to defend the important Tennessee and Cumberland rivers, respectively.
Fort Henry was a five-sided, open-bastioned earthen structure covering 10 acres on the eastern bank of the Tennessee River, near Kirkman's Old Landing and Standing Rock Creek, nearly opposite the mouth of the Sandy River.
Since Fort Donelson was on the west bank of the Cumberland, he selected the east bank of the Tennessee for the second fort so that one garrison could travel between them and be used to defend both positions, which he deemed unlikely to be attacked simultaneously.