The word that makes sense in the sentence is "secede."
Explanation:
1. After Abraham Lincoln was elected president in 1860, many Southern states voted to **secede** from the United States.
By seceding, these Southern states chose to withdraw or leave the United States and form their own separate government, which eventually led to the formation of the Confederate States of America. This decision was primarily driven by differences over issues such as slavery, states' rights, and the balance of power between the federal government and individual states. The act of secession played a significant role in triggering the American Civil War.
