The South could not break the blockade. But the North could tighten it, and did so repeatedly, not only at sea but by establishing strong strategic centers of its own along the Southern coast. We have seen already how Hatteras Island was taken in '61, five weeks after Bull Run. Within another three weeks Ship Island was also taken, to the great disadvantage of the Gulf ports and the corresponding advantage of the Federal fleet blockading them; for Ship Island commanded the coastwise channels between Mobile and New Orleans, the two great scenes of Farragut's success. Then, on the seventh of November, the day that Grant began his triumphant career by dealing the Confederates a shrewd strategic blow at Belmont in Missouri, South Carolina suffered a worse defeat at Port Royal (where she lost Forts Beauregard and Walker) than North Carolina had suffered at Hatteras Island. Admiral S. F. Du Pont managed the naval part of the Port Royal expedition with consummate skill, especially the fine fleet action off Hilton Head against the Southern ships and forts. He was ably seconded by General Thomas West Sherman, commanding the troops. North Carolina's turn soon came again, when she lost Roanoke Island (and with it the command of Albemarle Sound) on February 8, 1862; and when she also had Pamlico Sound shut against her by a joint expedition that struck down her defenses as far inland as Newbern on the fourteenth of March. Then came the turn of Georgia, where Fort Pulaski, the outpost of Savannah, fell to the Federals on the eleventh of April. Within another month Florida was even more hardly hit when the pressure of the Union fleet and army on Virginia compelled the South to use as reinforcements the garrison that had held Pensacola since the beginning of the war. These were all severe blows to the Southern cause. But they were nothing to the one which immediately followed. The idea of an attack on New Orleans had been conceived in June, '61, by Commander (afterwards Admiral) D. D. Porter, of the U.S.S. _Powhatan_, when he was helping to blockade the Mississippi. The Navy Department had begun thinking over the same idea in September and had worked out a definite scheme. New Orleans was of immense strategic importance, as being the link between the sea and river systems of the war. The mass of people and their politicians, on both sides, absurdly thought of New Orleans as the objective of a land invasion from the north. Happily for the Union cause, Gustavus Fox, Assistant Secretary of the Navy, knew better and persuaded his civilian chief, Gideon Welles, that this was work for a joint expedition, with the navy first, the army second. The navy could take New Orleans. The army would have to hold it.