As soon as it became evident that war was being waged against the United States in dead earnest, and that it was likely to be prolonged, these considerations presented themselves to the Government, and a plan was matured for capture of the largest city in the territory of the insurgents. {89} [Illustration: PANORAMIC VIEW OF NEW ORLEANS--FEDERAL FLEET AT ANCHOR IN THE RIVER.] The defences of New Orleans against an enemy approaching from the sea consisted of two forts, on either side of the stream, {90} thirty miles above the head of the five great passes through which it flows to the Gulf. The smaller, Fort St. Philip, on the left bank, was of earth and brick, with flanking batteries, and all its guns were _en barbette_--on the top, in plain sight. These numbered about forty. Fort Jackson, on the right bank, mounted seventy-five guns, fourteen of which were in bomb-proof casemates. Both of these works had been built by the United States Government. They were now garrisoned by about one thousand five hundred Confederate soldiers, commanded by Gen. Johnson K. Duncan. Above them lay a Confederate fleet of fifteen vessels, including an iron-clad ram and a large floating battery that was covered with railroad iron. Just below the forts a heavy chain was stretched across the river--perhaps suggested by the similar device employed to keep the British from sailing up the Hudson during the Revolutionary war. And it had a similar experience; for, at first supported by a row of enormous logs, it was swept away by the next freshet. The logs were then replaced by hulks anchored at intervals across the stream, and the chain ran over their decks, while its ends were fastened to great trees. One thing more completed the defence--two hundred sharp-shooters patrolled the banks between the forts and the head of the passes, to give warning of an approaching foe and fire at any one that might be seen on the decks. [Illustration: FROM PENSACOLA TO THE MOUTH OF THE MISSISSIPPI.] The idea at Washington, probably originated by Commander (now Admiral) David D. Porter, was that the forts could be reduced by raining into them a sufficient shower of enormous shells, to be thrown high into the air, come down almost perpendicularly, and explode on striking. Accordingly, the first care was to make the mortars and shells, and provide the craft to carry them. Twenty-one mortars were cast, which were mounted on twenty-one schooners. They threw shells thirteen inches in diameter, weighing two hundred and eighty-five pounds; and when one of them was discharged, the concussion of the atmosphere was so great that no man could stand close by without being literally deafened. Platforms projecting beyond the decks were therefore provided, for the gunners to step out upon just before firing. [Illustration: COMMANDER DAVID D. PORTER. (Afterward Rear-Admiral.)]