Early in March the raft, formed of great cypress trees, forty feet long and fifty inches through, laid lengthwise in the river about three feet apart, anchored by heavy chains and strengthened by massive cross-timbers, had been partly carried away by the flood. To make good the damage, a number of large schooners had then been anchored in the gap. On the morning of the 21st of April this formidable obstruction was cleverly and in a most gallant manner broken through by the fleet. On the night of the 23d of April, Farragut moved to the attack. His fleet, organized in three divisions of eight, three, and six vessels respectively, was formed in line ahead. The first division was led by Captain Bailey, in the _Cayuga_, followed by the _Pensacola, Mississippi, Oneida, Varuna, Katahdin, Kineo_, and _Wissahickon;_ the second division followed, composed of Farragut's flag-ship, the _Hartford_, Commander Richard Wainwright, the _Brooklyn_, and the _Richmond;_ while the third division, forming the rear of the column, was led by Captain Bell, in the _Sciota_, followed by the _Iroquois, Kennebec, Pinola, Itasca,_ and _Winona_. At half-past two o'clock on the morning of the 24th of April the whole fleet was under way; a quarter of an hour later the batteries of Forts Jackson and St. Philip opened simultaneously upon the _Cayuga_. It was some time before the navy could reply, but soon every gun was in action. Beset by perils on every hand, the fleet pressed steadily up the river. The Confederate boats were destroyed, the fire-rafts were overcome, the gunners of the forts were driven from their guns, and when the sun rose Farragut was above the forts with the whole of his fleet, except the _Itasca, Winona_, and _Kennebec_, which put back disabled, and the _Varuna_, sunk by the Confederate gunboats. The next afternoon, having made short work of Chalmette, Farragut anchored off New Orleans, and held the town at his mercy. The casualties were 37 killed and 147 wounded, in all 184. The Confederate loss was 50, 11 killed and 39 wounded. The _Louisiana, McCrea_, and _Defiance_, sole survivors of the Confederate fleet, escaping comparatively unhurt, took refuge under the walls of Fort St. Philip.