Controlling the Mississippi River was a key objective of the North's overall Civil War strategy. Included in the Union's river boat flotilla was the U.S.S. Cairo. The city class gunboat was built in Mounds City, Illinois in January,1862. The Cairo was one of seven formidable ironclads named after cities along the Mississippi and Ohio Rivers. The hull was built of white oak, covered in iron sheeting and fitted with 13 heavy cannons.
On December 12, 1862, the Cairo came under attack as it headed toward confederate batteries, just north of Vicksburg, Mississippi. Two quick explosions stopped the ironclad and the armor laden ship slipped out of sight, into the Mississippi River. The Cairo had been the first ship sunk with an electrically fired torpedo.
Edwin C. Bearss, historian at Vicksburg National Military Park, began a search along the river bottom for the missing Cairo. Some 90 years had passed when positive identification was issued. In 1965, the Cairo was raised from the muddy Mississippi and necessary preservation quickly began at the Ingalls Shipyard in Pascagoula. In June, 1977, the Cairo was returned to Vicksburg. Today, the ship, and museum filled with Cairo artifacts, is on display at the military park, adjacent to the Vicksburg National Cemetery.