Ship Island is located just off the coast of Mississippi, half way between New Orleans and Mobile. It had been fortified well before the outbreak of the civil war, and helped to protect the Confederate coastal trade. It had been occupied by the Confederates early in July 1861, initially by a force of 140 men, although that was soon reinforced.
Their possession of the island was soon discovered. On 8 July a U.S. Navy ship, the Massachusetts, discovered that the lighthouse on Ship Island had been extinguished. The next morning the ship was fired on by the new Confederate garrison. A short artillery duel followed, after which the Massachusetts continued on her way. The navy department were keen to capture the island, but for the rest of the summer the best the navy could do was have the Massachusetts keep an eye on the place.
Finally, in September 1861, with two more Federal ships on the horizon, the commander of the Confederate garrison, Lieutenant-Colonel Allen, was ordered to evacuate the island. On 16 September he destroyed as much of the fort as he could. The next day he evacuated the island, leaving behind a note to the captain of the Massachusetts, Commander Melancton Smith. Smith occupied the island on the same day, holding it with a small naval force until the army took over at the end of November.
Ship Island was used as the headquarters of the West Gulf squadron. It provided a convenient base during David Farragut’s campaign against New Orleans in April 1862. After the Confederates abandoned Pensacola on 9 May 1862 the squadron moved its base to that much superior harbour. Even after that, Ship Island remained a useful supply depot for the Union fleet in the gulf.