The correct answer is the Union's attempt to give resources and supplies to Fort Sumter.
Fort Sumter was an American military fort in South Carolina. After the state of South Carolina seceded just a few short weeks after the presidential eleciton of 1860, the fort remained under the control of the US government. A few months after secession, the South Carolinians had not interfered with the Fort nor were planning on attacking this fort.
However, tensions would rise when the Union sent more supplies and troops to this fort. The government of South Carolina as the Union preparing for war. The Confederacy attacked Fort Sumter, leading to the first battle of the US Civil War.
