A month before the fight between the _Monitor_ and _Merrimac_, a formidable naval expedition under Commodore Goldsborough and General Ambrose E. Burnside passed down the Atlantic coast and captured Roanoke Island. St. Augustine and a number of other places in Florida were captured by troops from Port Royal. Siege was laid to Fort Pulaski, at the mouth of the Savannah River, and it surrendered April 11th. The advantage of these and similar captures was that it gave the blockading fleets control of the principal harbors, and made it easier to enforce a rigid blockade. There were two ports, however, which the Union vessels were never able to capture until the close of the war. They were Charleston and Wilmington, North Carolina. The latter became the chief port from which the Confederate blockade-runners dashed out or entered and were enabled to bring the most-needed medical and other supplies to the Confederacy, while at the same time the owners and officers of the ships reaped fortunes for themselves. CAPTURE OF NEW ORLEANS. One of the primal purposes of the war was to open the Mississippi, which was locked by the enemy at Vicksburg and New Orleans. As a necessary step in the opening of the great river, an expedition was fitted out for the capture of New Orleans. Well aware of what was coming, the Confederates had done all they could to strengthen the defenses of the city. Thirty miles from the mouth of the Mississippi were the powerful Forts Jackson and St. Philip, on opposite sides of the river. They mounted 100 heavy guns, and six powerful chains were stretched across, supported by an immense raft of cypress logs. Thus the river was closed and no fleet could approach New Orleans until these obstructions were removed or overcome. When this should be done, it was still seventy-five miles to New Orleans. Above the boom of hulks and logs was a fleet of fifteen Confederate vessels, including the ironclad ram _Manassas_, and a partly completed floating battery armored with railroad iron, and known as the _Louisiana_. It has been stated that the ironclads of those days were only partly protected by armor. The naval and military expedition which sailed for New Orleans in the spring of 1862 consisted of six sloops of war, sixteen gunboats, five other vessels, and twenty-one mortar-schooners, the last being under charge of Captain David D. Porter, while Commodore David G. Farragut had command of the fleet. The troops, mostly from New England, were commanded by General B.F. Butler.