Political map of North America & the Caribbean 12 April 1861 (Attack on Fort Sumter): Despite the Confederacy (Confederate States of America)'s declaration of independence, the United States Army still garrisoned a number of forts in the south. The most vulnerable was Fort Sumter in Charleston harbor, South Carolina, which desperately needed to be resupplied. However when newly elected US President Lincoln (Abraham Lincoln) ordered the navy to ship in supplies, the Confederate government considered it an act of war and attacked the fort from land (Battle of Fort Sumter). The American Civil War had begun.