Fort Morgan (Alabama) in the context of Fort Gaines (Alabama)

Alabama was central to the Civil War, with the secession convention at Montgomery, the birthplace of the Confederacy, inviting other slaveholding states to form a southern republic, during January–March 1861, and to develop new state constitutions. The 1861 Alabamian constitution granted citizenship to current U.S. residents, but prohibited import duties (tariffs) on foreign goods, limited a standing military, and as a final issue, opposed emancipation by any nation, but urged protection of African-American slaves with trials by jury, and reserved the power to regulate or prohibit the African slave trade. The secession convention invited all slaveholding states to secede, but only 7 Cotton States of the Lower South formed the Confederacy with Alabama, while the majority of slave states were in the Union at the time of the founding of the Confederacy. Congress had voted to protect the institution of slavery by passing the Corwin Amendment on March 4, 1861, but it was never ratified.

Even before secession, the governor of Alabama Andrew B. Moore defied the United States government by seizing the two federal forts at the Gulf Coast (forts Morgan and Gaines) and the arsenal at Mount Vernon in January 1861 to distribute weapons to Alabama towns. The peaceful seizure of Alabama forts preceded by three months the bombing and capture of the Union's Fort Sumter (SC) on April 12, 1861.

Mobile Bay (/moʊˈbiːl/ moh-BEEL) is a shallow inlet of the Gulf of Mexico, lying within the state of Alabama in the United States. Its mouth is formed by the Fort Morgan Peninsula on the eastern side and Dauphin Island, a barrier island on the western side. The Mobile River and Tensaw River empty into the northern end of the bay, making it an estuary. Several smaller rivers also empty into the bay: Dog River, Deer River, and Fowl River on the western side of the bay, and Fish River on the eastern side. Mobile Bay is the fourth-largest estuary in the United States with a discharge of 62,000 cubic feet (1,800 m) of water per second. Annually, and often several times during the summer months, the fish and crustaceans will swarm the shallow coastline and shore of the bay. This event, appropriately named a jubilee, draws a large crowd because of the abundance of fresh, easily caught seafood.

Mobile Bay is 413 square miles (1,070 km) in area. It is 31 miles (50 km) long by a maximum width of 24 miles (39 km). The deepest areas of the bay are located within the shipping channel, sometimes in excess of 75 feet (23 m) deep, but the average depth of the bay is 10 feet (3 m).