Abraham Lincoln: The 16th President of the United States who won the Election of 1860 and was seen as a threat by Southern states due to his anti-slavery stance.
Secession: The act of formally withdrawing or separating from an organization or alliance, in this case, referring to Southern states leaving the United States.
Slavery: The practice of owning other individuals as property and forcing them into forced labor without pay. Slavery played a central role in causing Southern states to secede after the Election of 1860.