On February 6, 1862 a group of river steamers, many which had been converted into so-called ironclads, approached the Confederate stronghold Ft. Henry, on what is now the Tennessee River. General Grant had landed a large number forces near Cairo, Illinois that were supposed to attack the fort, the river gunboats however arrived before the troops and took the fort under fire. For those left at Ft. Henry conditions were difficult, much of the fort was underwater due to the river rising and most of her guns were unusable. The gun crews were at a disadvantage because the guns could not be lowered enough to be as effective as they should have been, but they did hit one of the gunboats.

USS Essex was hit amidships by a 32 pounder, the shell penetrated her thin iron shield and hit the boiler, which burst. The scalding hot water killed eleven crewmen, and badly injured another twenty-three, including the commanding officer William D. Porter. Despite his injuries he remained in command of the ship and got her clear of the action. Shortly after the battle began the fort surrendered. Perhaps the most ironic part of the story is that the fort was completely underwater only a couple of days later.