In late summer 1864, a Union combined force initiated operations to close Mobile Bay to blockade running vessels from the Gulf of Mexico port city of Mobile, Alabama. On August 3rd, 1,500 Union infantry and cavalrymen under Maj. Gen. Gordon Granger landed on Dauphin Island and laid siege to Fort Gaines west of the ship channel. On August 5th, Admiral David G. Farragut’s Union fleet of eighteen ships, including four ironclad monitors, entered Mobile Bay in a double column and received a devastating fire from both Fort Gaines and Fort Morgan, east of the channel. Farragut's fleet successfully navigated the narrow, torpedo-filled passage, losing only the ironclad USS Tecumseh. After successfully passing both forts, Farragut engaged the small Confederate naval force inside the harbor under Adm. Franklin Buchanan, including the ironclad ram CSS Tennessee, and forced it to surrender. Without naval support, the garrisons of both forts were vulnerable and could not be resupplied. Farragut and Granger next turned their attention to Fort Gaines, forcing it to surrender on August 8th. Fort Morgan, the larger of the two forts, held out longer, finally surrendering on August 23rd. The loss of the Confederate fleet and forts essentially shut down the port, although the city of Mobile would not surrender until three days after Lee's surrender at Appomattox.