Explain the sequence of secession following Lincoln's election, the formation of the Confederacy, and the attack on Fort Sumter that began the Civil War.
South Carolina made good on its threat first, seceding from the Union on December 20, 1860, just weeks after Lincoln's election. By February 1861, six more Deep South states -- Mississippi, Florida, Alabama, Georgia, Louisiana, and Texas -- had followed, and delegates met in Montgomery, Alabama to form the Confederate States of America, electing Jefferson Davis as their president. When Lincoln was inaugurated in March 1861, he insisted he had no intention of invading the South or ending slavery where it already existed, but that he would not accept secession and would hold federal property in the South.
That federal property included Fort Sumter, a Union fort sitting in the harbor of Charleston, South Carolina. When Lincoln announced he would resupply the fort with food (not weapons or troops), Confederate forces under General P.G.T. Beauregard opened fire on it on April 12, 1861, and the fort surrendered the next day. No one was killed in the bombardment itself, but the attack made the war unavoidable: Lincoln called for 75,000 volunteers to put down the rebellion, and rather than send troops against fellow Southerners, four more states -- Virginia, North Carolina, Tennessee, and Arkansas -- seceded and joined the Confederacy. Four remaining slave states along the border -- Missouri, Kentucky, Maryland, and Delaware -- stayed in the Union, a fact that shaped Lincoln's cautious early strategy on slavery.
Mastery looks like: They can sequence secession, the formation of the Confederacy, and the attack on Fort Sumter accurately, and explain why the border states' choice to remain in the Union mattered.
Common stumbles: Assuming all eleven Confederate states seceded at the same time and for the same immediate trigger, rather than understanding the two-wave process around Fort Sumter.