Images of Mobile, Alabama. From Harper's Weekly:
After New Orleans, Mobile was the most important port on the Gulf coast for the Confederacy. When New Orleans fell in the spring of 1862, Mobile became the most important port on the Gulf coast.
There were a number of reasons for this port’s value. Mobile Bay was an embayment running in a north-south direction, with a narrow mouth at the south end, guarded by Forts Morgan and Gaines (which were both under construction at the beginning of the Civil War). The City of Mobile lay at the northern end of the bay. Any naval assault on the city would have to pass through the mouth, run the gauntlet past the forts, and then up the bay to the city. Two major river systems, the Tombigbee and Alabama Rivers, converged at Mobile and provided river access to the interior. Mobile itself had a foundery and ship building facilities, and upriver the City of Selma had additional industrial capability.
In addition, several major railroad lines linked Mobile to other parts of the Confederacy, and provided the main link between the eastern and western portions of the CSA. Mobile’s rail connections proved to be of immense military value to the Confederacy, enabling the movement of troops to critical areas where and when they were needed. Confederate Gen. Braxton Bragg, when he was garrisoning Pensacola, Florida, considered the ability to easily move troops by rail between Mobile and Pensacola, “worth 3,000 men at each end.”
Mobile was among the last major southern cities to fall at the end of the war. Yet, this defeat had no influence on the ultimate outcome of the war, as by 1865 (when the city was taken), the war was already won by the North. If the city has been taken earlier in the war (say, in 1862), historians estimate that this would have ended the war much sooner than it ultimately did. Interestingly, it seems both northern and southern leadership acknowledged the importance of Mobile and Mobile Bay, but both sides did not allocate the military resources to take or defend the city.
Through much of the war, Mobile remained an important port for blockade running, bringing critically needed supplies into the Confederacy and distributing them to where they were needed.