Answer:
Florida, Georgia, Alabama, Mississippi, and Louisiana reacted to South Carolina's secession by seceding as well and joining to form the Confederate States of America.
Step-by-step explanation:
In 1860, the abolitionist Republican Abraham Lincoln won in the presidential elections. South Carolina, fearing that Lincoln would definitively abolish slavery in the country, decided to separate from the United States. The state did so on December 20 of that year, being the first US state to separate itself from the rest of the country. Subsequently, ten other states (including Florida, Georgia, Alabama, Mississippi and Louisiana) would also be separated from the United States, and immediately join to form the Confederate States of America.