What is the reasoning behind Lincoln's referring to the South as the rebellion?

Answer 1

Lincoln referred to the South as the "rebellion" to emphasize that the conflict was not merely a regional dispute but an insurrection against the established government of the United States. By framing it this way, he sought to legitimize the Union's efforts to restore order and uphold the Constitution. This terminology also aimed to unify the North and rally support for the war effort against those he viewed as undermining the nation's unity and democratic principles. Overall, it reinforced his stance that the Union was fighting to preserve the nation rather than to suppress a legitimate movement for independence.