While the land forces were fighting at Shiloh and elsewhere, the Union navies continued to work towards the capture of the Mississippi River. After Island Number 10 was captured, the Union gunboats moved down to Fort Pillow. The fleet lacked infantry to take the fort, so an ironclad and a mortar boat were stationed to throw a shell into the fort ever half hour, while the other seven gunboats remained upstream out of danger at Plumb Point Bend. The commander of the fleet, Andrew Foote, left the command because of a wound he had received at Fort Donelson. He was replaced by Commodore Charles Henry Davis, a long time navy officer. The day after he took command, May 10th, 1862, he was attacked by a Confederate flotilla. It was composed of eight small gunboats from under J. E. Montgomery, a river boat captain. The ships were from New Orleans, part of what was called the River Defense Fleet. They were civilian steamboats that had been converted for military use, and were called cottonclads because of the practice of putting bales of cotton to protect from enemy shot. Although they were much weaker than the true ironclads, they hoped to make up in daring and surprise what they lacked in firepower.
They struck at 7:00. The ironclad Cincinnati guarding the mortar boat, but the captain was not expecting an attack and the ship did not have steam up in her boilers, meaning she was immobile. When they sighted the rebel rams coming up river, they had only eight minutes to react. They tried throwing whatever flammable they could find in the furnaces, but were still unprepared when the steamboats arrived. The Cincinnati fired a broadside at the lead ship, the General Bragg, but was then struck by the ram. A twelve foot hole was tore in her side, flooding the magazine. The Sumter and Colonel Lovell also rammed, making more holes in the Cincinnati and sending her quickly to the bottom. Now the Mound City arrived, having been sent by Davis to assist the Cincinnati. She arrived too late to save the Cincinnati, and the General Van Dorn crashed through her starboard side, sending a second ironclad to the bottom. Montgomery fell back to Fort Pillow not wanting to risk a battle with the other five ironclads. But he had gloriously shown that ironclads could be sunk, and it seemed possible that these little rams might be able defeat the federal fleet. But they were not enough to save Fort Pillow. It was abandoned on July 4th to keep from getting cut off from the rest of the Confederate armies.