Alabama's Mobile Bay became increasingly important to the Confederacy as the war progressed. The Union blockade had effectively closed other ports, but Mobile Bay was still relatively free, making it the only open Gulf port east of Texas and the primary site for the smuggling of arms and provisions from Europe. David Farragut, promoted in July 1862 to rear admiral, wanted to launch an assault on the port immediately following his success at New Orleans in April 1862, but circumstances forced him to wait until January 1864 to begin preparations, though the attack itself wouldn't come for another seven months.

When the time came, however, Farragut had an impressive fleet behind him: fourteen wooden boats and four ironclads. He began the assault early on the morning of August 5, easing the fleet into the bay, which was heavily mined with explosives, known as torpedoes. The fleet was met by heavy Confederate gunfire from Fort Morgan, the bay's main defense, as well as a Confederate fleet of three wooden gunboats and the South's largest ironclad, the CSS Tennessee, led by Confederate admiral Franklin Buchanan.

As the battle commenced, Farragut tied himself high in the rigging of his flagship, the Hartford, so that he could better direct his ships. From his perch, he watched his lead ironclad, the Tecumseh, strike a mine and sink with almost all hands in a matter of minutes. The rest of Farragut's ships stopped where they were, confused and fearful of other mines, as the cannons at Fort Morgan continued to roar. It was then that Farragut shouted the rallying words for which he is still remembered today: “Damn the torpedoes! Full speed ahead!” Moving the Hartfordout in front, Farragut successfully led the rest of his fleet through the minefield and past the fort into Mobile Bay.

The Tennessee, commanded by Buchanan himself, tried to ram the Union ships, then engaged in a gun battle with them before slinking off to safe harbor at Fort Morgan. The Union crews took that quiet moment to have a quick breakfast, only to have their meal interrupted by the Tennessee, which returned for another attack. The Confederate ironclad was a formidable ship, but Buchanan soon found himself surrounded by Union vessels, which rammed and fired upon his ship until it was a helpless hulk. Buchanan was injured during the battle and his ship surrendered. In just four hours, Mobile Bay had come under Union control. Fort Morgan, however, was not captured until August 23, and the city of Mobile would remain in Confederate hands until the end of the following April.