The naval forces were under the command of Admiral Farragut, while Commander Porter had charge of the mortar fleet.
The principal defences below the city were Forts Jackson and St.Philip.
In approaching them Porter had his ships dressed out with leaves and branches of trees, the clever disguise proving an effectual protection from a very destructive fire.
The furious bombardment lasted for several days and nights.

The river was spanned by a boom of logs, which it was necessary to break through that the vessels might reach the city above.

This was done, Porter protecting the expedition which effected it.

When the situation of the forts became hopeless his demand for their surrender was accepted and an officer came on board under a flag of truce to complete the negotiations.
While Porter and his visitor were conversing an officer came forward with the information that the immense floating battery _Louisiana_, of four thousand tons burden and carrying sixteen heavy guns, had been set on fire, as Admiral Cervera did with his ships a generation later, when his escape was cut off from Santiago.
"Such an act is anything but creditable to you," remarked Porter, addressing the Confederate commander.
"I am not responsible for the acts of the naval officers," replied the visitor.
The explanation was reasonable, and without any excitement, Commander Porter renewed the conversation respecting the surrender, but a few minutes later the officer again approached.
"The ropes which held the floating battery to the bank have been burned and she is drifting down stream toward us." "Are her guns loaded and is there much ammunition aboard ?" asked Porter of the Confederate commander.
"I suppose the guns are loaded, but I know nothing about naval matters here," was the reply.
Just then the heated cannon began firing their huge charges, which, though without aim, were likely to do injury to the Union vessels toward which the battery was floating.

Besides, the magazine was stored with powder and the impending explosion could not fail to be disastrous.
"If you do not mind it," said Porter, addressing the visitor, "we will continue our negotiations." In referring to this incident, the Admiral said: "A good Providence, which directs the most important events, sent the battery off toward Fort St.Philip, and, as it came abreast of that formidable fort, it blew up with a force which scattered the fragments in all directions, killing one of their own men in the fort, and when the smoke cleared off it was nowhere to be seen, having sunk immediately in the deep water of the Mississippi.