Battle of Mobile Bay - Mobile and Mobile Bay

Mobile and Mobile Bay

Mobile is situated near the head of Mobile Bay, a natural harbor formed where the Mobile and Tensaw rivers meet before they enter the Gulf of Mexico. The bay is about 33 mi (53 km) long; the lower bay is about 23 mi (37 km) at its greatest width. It is deep enough to accommodate ocean-going vessels in the lower half without dredging; above the mouth of Dog River the water becomes shoal, so deep-draft vessels could not approach the city.

The mouth of the bay is marked on the east by a long narrow peninsula of sand, Mobile Point, that separates Bon Secour Bay, where the Bon Secour River enters the larger bay, from the gulf. The land ends at the main channel into Mobile Bay, and here the United States (U.S.) government had erected a fort in more peaceful times to shield Mobile from possible enemy fleets.

Across the entrance, the line of the peninsula is continued in a series of barrier islands, beginning with Dauphin Island. Northwest of Dauphin Island is Little Dauphin Island, then a series of minor islands that are interrupted by a secondary entrance to the bay, Grant's Pass. A few other small islands and shoals lie to the south of Dauphin Island, defining the main channel for as much as 10 mi (16 km) south of the entrance.

Rather early in the war, the Confederate government decided not to defend its entire coast, but to concentrate its efforts on a few of its most important ports and harbors. Following the loss of New Orleans in April 1862, Mobile was the only major port on the eastern gulf that would be defended.

The city subsequently became the center for blockade running on the gulf. Most of the trade between the Confederacy and Havana and other Caribbean ports passed through Mobile. A few attempts were mounted to break the blockade, but they were not large enough to have lasting impact. Among the most embarrassing episodes of the war for the U.S. Navy was the passage of the raider CSS Florida through the blockade into Mobile Bay on September 4, 1862; this was followed by her later escape through the same blockade on January 15, 1863.

Although the orders given to Flag Officer David G. Farragut when he was assigned to command of the West Gulf Blockading Squadron had included instructions to capture Mobile as well as New Orleans, the early diversion of the squadron into the campaign for the lower Mississippi meant that the city and its harbor would not receive full attention until after the fall of Vicksburg in July 1863.

Given respite by the Union strategy, the Confederate Army improved the defenses of Mobile Bay by strengthening Fort Morgan and Fort Gaines at the entrance to the bay. In addition, they set up the smaller Fort Powell, a work that guarded the Grant's Pass channel. Grant's Pass was also obstructed by a set of piles and other impediments, which had the effect of diverting the tidal flow to Heron Pass.