All along the banks of the river were thick woods. The forts themselves were almost hidden by the trees. Captain Farragut stationed his mortar boats close to the banks, below the chain barricade; and, in order that they might be better hidden from the forts, large branches of trees had been tied to the tops of the masts. This mortar flotilla was commanded by Captain Porter. The mortars could throw thirteen-inch shells for a distance of two miles. Captain Farragut's plan was to send these mortar boats forward to bombard the forts, while the other vessels, breaking through the chains, should sail boldly up the river. On the morning of April 18th, the shells from the mortars began to rain down upon the forts. For six days and nights this firing never ceased. The answering shots from the forts did but little harm. The Confederates could not take aim at boats which they could not see. Meanwhile, two of Captain Farragut's gunboats crept up the river at night, and broke a passage through the chain barricade. Then, on the night of April 23d, the entire fleet sailed through this opening and boldly attacked the forts. The whole river was at once a scene of confusion. Every gun, both of the forts and of the Confederate fleet, which had hastened down the river, was sending shot and shell into the Union fleet. The Confederates piled every kind of inflammable material upon huge rafts, set them on fire, and sent them floating down the river. They hoped, in this way, to burn the invading fleet. The river was a blaze of light. The din from the cannon was terrible. But Captain Farragut and his vessels kept steadily on. They passed the forts, and destroyed or captured every vessel in the Confederate fleet. This was accomplished with the loss of but one ship of the Union squadron. When the news of this victory reached New Orleans, the whole city was thrown into wild confusion. Men, women, and children rushed to the levee and set fire to the goods there. Everything that would burn was set on fire, and sent down the river to meet the victorious fleet that was coming. Ships loaded with burning cotton, and even a half-finished ram like the _Merrimac_ floated down stream, a mass of flames. [Illustration: GENERAL B.F. BUTLER.] About noon on April 25th, the fleet rounded the bend of the river, and came in sight of the city. That same morning, the mayor of New Orleans had ordered the state flag of Louisiana to be hoisted upon the city hall. Captain Farragut demanded that this should be hauled down. He also ordered that the stars and stripes should be raised over the buildings belonging to the United States government. Meanwhile, Commander Porter with his mortar boats had been steadily bombarding Fort Jackson and Fort St. Philip. On April 28th, these forts surrendered, and the Union forces took possession.